A 


SYSTEM  OF  ANATOMY 

Foil  THE  USE  OF 

'* 

STUDENTS  OF  MEDIC.-  I 


BY  CASPAR  WISTAR,  M.  I). 

LATE  PROFESSOR  OF  ANATOMY  IN  THE  IT  NITERS  ITT -OF  i'EJVNSYLTANI.'. 


FOURT  H EDITION. 

WITH  NOTES  AND  ADDITIONS- 


BY  WILLIAM  EDMONDS  HORNY  ;N  M.  X). 

AT  -JIT^T  PROFESSOR  OF  AWAT03I."  IN  THE  TjSm-AS!  ~ ■ 

^ 7^A,  MEMBER  Ot  THE  A3lERICA:-r  PHi'.':?0T,ni'  . 

Of  — 

IN  TWO  VOLUMES  — VOL.  II. 


PHILADELPHIA: 

CAREY,  LE  4 i-  r ' P .THE  l ; UT  STREE 


1827 


M ■ as  • 


♦ 


EASTERN  DISTRICT  OF  PENNSYLVANIA,  TO  WIT; 

BE  IT  REMEMBERED,  that  on  the  twentieth  day 
of  August  in  the  forty-ninth  year  of  the  Independence  of 
the  United  States  of  America,  A.  D.  1825,  H.  C.  Carey 
& I.  Lea,  of  the  said  district,  have  deposited  in  this  office 
the  title  of  a book,  the  right  whereof  they  claim  as  Pro- 
prietors, in  the  words  following,  to  wit: 

cc  A System  of  Aanatomy  for  the  use  of  Students  of  Medicine,  By 
“ Caspar  Wistar,  M.  D.  Late  Professor  of  Anatomy  in  the  Universi- 
ty of  Pennsylvania.  Third  edition.  With  notes  and  additions.  By 
“ William  Edmonds  Horner,  M.  D.  Adjunct  Professor  of  Anatomy 
in  the  University  of  Pennsylvania,  and  member  of  the  American 
Philosophical  Society,  &c.  In  two  volumes.  Volume  II.55 

In  conformity  to  the  act  of  the  Congress  of  the  United  States,  entitled. 
An  Act  for  the  Encouragement  of  Learning,  by  securing  the  copies  of 
Maps,  Charts,  and  Books,  to  the  authors  and  proprietors  of  such  copies, 
'during  (lie  times  therein  mentioned.”  And  also  to  the  act,  entitled, 

.'  t supplementary  to  an  Act,  entitled  “ An  Act  for  the  Encouraged^^^ 
of  Learning,  by  securing  the  copies  of  Maps,  Charts,  and  Books, 

••.•‘hors  and  proprietors  of  such  copies  during  the  times  therein  mentionM^^ 
ml  extending  the  benefits  thereof  to  the  arts  of  designing,  engraving,  and 
< r 1 ,ing  historical  and  o,her  print?.” 

D.  CALDWELL, 

Clerk  of  the  Eastern  District  of  Pennsylvania. 


CONTENTS  OF  VOL.  II. 


PART  VI. 


OP  THE  NOSE— THE  MOUTH— AND  THE  THROAT. 
CHAPTER  I. 

Of  the  Nose. 

SECTION  I. 


Op  the  External  Nose  - 

SECTION  IL 
Of  the  Cavities  of  the  Nose 


CHAPTER  II. 


Of  the  Mouth  and  the  Salivary  Glands. 

C 7 the  Mouth  - = 14 

Of  the  Salivary  Glands  ------  25 


CHAPTER  III. 
Of  the  Throat. 
SECTION  I. 

Of  the  Isthmus  of  the  Fauces 

SECTION  II. 

Of  the  Larynx  - 
Of  the  Thyroid  Gland  - 

SECTION  m. 

Of  the  Pharynx  - 


29 

31 

37 

37 


IV 


• •ox  TEXTS. 


PART  VII. 

OF  THE  THORAX. 
CHAPTER  I. 

Of  the  General  Cavity  of  the  Thorax. 
SECTION  I. 


Of  the  Form  of  the  Cavity  of  the  Thorax 

44 

SECTION  II. 

Of  the  Arrangement. of  the  Pleurae 
Preparation  of  the  Thorax  - 

45 

47 

CHAPTER  II. 

Of  the  Heart  and  the  Pericardium,  and  the  Great  Vessels 
connected  with  the  Heart. 

SECTION  I. 

Of  the  Pericardium  - ■ - 

49 

SECTION  II. 

\ 

Of  the  Heart  ------ 

50 

SECTION  III. 

Of  the  Aorta,  the  Pulmonary  Artery  and  Veins, 
Venae  Cavae  at  their  commencement 

and  the 

59 

CHAPTER  III. 

Of  the  Trachea  and  Lungs. 

SECTION  L 

Of  the  Trachea 

The  Black  Glands  on  the  Bronchia; 

62 

64 

SECTION  II. 

Of  the  Lungs 

Thorax  of  the  Foetus 

Physiological  observations,  &c.  ... 

65 

69 

71 

OOMTENTSo 


V 


PART  VIII. 

OF  THE  abdomen, 

CHAPTER  I. 

A general  view  of  the  Abdomen  and  Pelvis , aim  their  Con- 
tents ; with  an  Account  of  the  Peritoneum . 


SECTION  I. 


Construction  of  the  Abdomen  - 

- 

- 

- 

SB 

Contents  of  the  Abdomen 

- 

- 

- 

85 

SECTION  II. 

Of  the  Peritoneum  - 

- 

- 

- 

90 

CHAPTER  II. 

Of  the  (Esophagus , the  Stomach,  and  the  Intestines . 

SECTION  I. 

Of  the  (Esophagus 

- 

- 

- 

94 

SECTION  II. 
Of  the  Stomach  - - 

' J 

96 

0.f  the  Gastric  Liquor  - 

- 

- 

■ - 

10; 

SECTION  III. 

Of  the  Intestines  - 

104 

Division  of  the  Intestines 

. 

- 

- 

109 

The  Small  Intestines  - 

. 

- 

110 

The  Duodenum  - 

- 

. 

- 

111 

Jejunum  and  lieon  - 

- 

. 

- 

113 

The  Mesentery  - 

- 

- 

- ■ 

115 

Ot  the  Great  intestines  - 

- 

- 

-> 

117 

The  Caecum  and  Colon  ... 

- 

- 

118 

The  Rectum  - 

*, 

• 

122 

The  Omentum  - 

• 

. 

125 

CHAPTER  III. 

Of  the  Liver , the  Pancreas , and  the  Spleen. 
SECTION  I. 

Of  the  Liver  - _ „ _ , * „ iQS 


Vi  CONTENTS. 

SECTION  II. 

Of  the  Pancreas  141 

SECTION  III. 

Of  the  Spleen  145 

CHAPTER  IV. 

Of  the  Urinary  Organs , and  the  Glandulse  Renales. 
SECTION  I. 

Of  the  Glandulse.  Renales  - - - - 154 

SECTION  II. 

Of  the  Kidneys  and  Ureters  - - - - 155 

SECTION  III. 

Of  the  Urinary  Bladder 162 

CHAPTER  V. 

Of  the  Male  Organs  of  Generation . 

SECTION  I. 

Of  the  Testicles  and  their  Appendages  = - * 171 

SECTION  II. 

*)f  the  Vesiculae  Seminales  and  the  Prostate  Gland  - 181 

SECTION  III. 

Of  the  Penis - ■■  -184 

CHAPTER  VI. 

Of  the  Female  Organs  of  Generation. 

SECTION  I. 

Of  the  External  Parts  of  Generation  - 200 

SECTION  II. 

Of  the  Vagina  - 203 

SECTION  III. 

Of  the  Uterus,  the  Ovaries,  and  their  Appendages  - 205 

SECTION  IV. 

Of  the  Bladder  and  Urethra  - 


213 


CONTENTS)  Vii 

PART  IS. 

OF  THE  BLOOD  VESSELS. 

CHAPTER  I. 

Of  the  General  Structure  and  arrangement  of  the  Blood  Vessels, 
SECTION  I. 

Of  the  Arteries  -------  226 

SECTION  II. 

Of  the  Veins  - --  --  --  - 233 

CHAPTER  II. 

A Particular  Aeeount  of  the  Distribution  of  the  Arteries. 

SECTION  I. 

Of  the  Aorta,  or  the  Great  Trunk  of  the  Arterial  System  236 
SECTION  II. 

Of  the  Branches  which  go  off  from  the  Arch  of  the  Aorta  23S 
SECTION  III. 

Of  the  Branches  which  go  off  between  the  Arch  and  the 
Great  Bifurcation  of  the  Aorta  - 2r2 

SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the  Great 
Bifurcation  of  the  Aorta  -----  283 

CHAPTER  III. 

Of  the  particular  Distribution  of  the  Veins, 

SECTION  I. 

Of  the  Superior,  or  Descending  Vena  Cava,  and  the 
Veins  which  communicate  with  it  - 300 

SECTION  It 

Of  the  Inferior  Vena  Cava,  and  the  veins  connected 
with  it  - - - - - - 


309 


via 


CONTENl  S. 


PART  X. 


OF  THE  NERVES 


Nerves  of  the  Brain  - 

- 

- 

3!23 

Of  the  Cervical  Nerves  - 

_ 

- 

343 

Nerves  of  the  Diaphragm 

346 

Brachial  Plexus  - 

- 

347 

Nerves  of  the  Arm  - 

- 

- 

348 

The  Dorsal  Nerves  - 

. 

- 

352 

Of  the  Lumbar  Nerves  - 

- 

- 

353 

The  Sacral  Nerves  - 

- 

- 

356 

Sciatic  Plexus  - 

- 

- 

3 57 

Great  Sciatic  Nerve 

. 

- 

358 

Great  Sympathetic  Nerve 

. 

- 

361 

Nerves  of  the  Heart  - 

- 

- 

363 

Nerves  of  the  Abdominal  Viscera  - 

- 

- 

368 

PART  XL 

OF  THE  ABSORBENT  VESSELS. 

CHAPTER  I. 

k 

Of  the  ./2b sorbents  of  the  Lower  Extremities — the  Abdomen 
and  the  Thorax, 

SECTION  I. 

i"  e Absorbents  of  the  Lower  Extremities  - - 376 

SECTION  II. 

The  Absorbents  of  the  Abdomen  and  Thorax  - - 381 

CHAPTER  II. 

Of  the  Absorbents  of  the  Head  and  Neel',  of  the  Upper  Ex- 
fremiti  f \ and  the  Upper  Part  of  the  Trunk  of  the  Body. 


SECTION  I. 

Of  the  Absorbents  of  the  Head  and  Neck  - - 391 

SECTION  II. 

• >f  the  Absorbents  of  the  Arm,  and  Upper  Part  of  the 

Trunk  - - - - - - SOS 


SYSTEM  OF  ANATOMY, 


PART  VI. 


OF  THE  NOSE:  THE  MOUTH  AND  THE  THROAT. 


CHAPTER  I. 


OF  THE  NOSE. 

The  prominent  part  of  the  'face,  to  which  the 
word  nose  is  exclusively  applied  in  ordinary  lan- 
guage, is  the  anterior  covering  of  two  cavities  which 
contain  the  organ  of  smelling. 

These  cavities  are  formed  principally  by  the  upper 
maxillary  and  palate  bones;  and,  therefore,  to  acquire 
a complete  idea  of  them,  it  is  necessary  to  study  these 
bones,  as  well  as  the  os  ethmoides,  the  vomer,  and 
the  ossa  spongiosa  inferiora,  which  are  likewise  con- 
cerned in  their  formation. 

In  addition  to  the  description  of  these  bones,  in 
the  account  of  the  bones  of  the  head,  it  will  be  use- 
ful to  study  the  description  of  the  cavities  of  the  nose 
which  follows  it.  See  vol.  I.  page  64. 

After  thus  acquiring  a knowledge  of  the  bony  struc- 
ture, the  student  will  be  prepared  for  a description 
of  the  softer  part's 

VnL,  u.  1 


3 


The  External  Nose, 


SECTION  i. 

Of  the  External  Nose. 

The  superior  part  of  the  nose  is  formed  by  the 
ossa  nasi,  and  the  nasal  processes  of  the  upper  max- 
illary bones,  which  have  been  already  described;  (see 
vol.  I.  pages  42 — 46,)  hut  the  inferior  part,  which 
is  composed  principally  of  cartilages,  is  much  more 
complex  in  its  structure. 

The  orifice,  formed  by  the  upper  maxillary  and 
nasal  bones,  is  divided  by  a cartilaginous  plate, 
which  is  the  anterior  and  inferior  part  of  the  sep- 
tum, or  partition  between  the  two  cavities  of  the 
nose.  The  anterior  edge  of  this  plate  projects  be- 
yond the  orifice  in  the  bones,  and  continues  in  the 
direction  of  the  suture  between  the  ossa  nasi.  This 
edge  forms  an  angle  with  the  lower  edge  of  the  same 
cartilage,  which  continues  from  it,  in  a horizontal 
direction,  until  it  reaches  the  lower  part  of  the  ori- 
fice of  the  nose,  at  the  junction  of  the  palatine  pro- 
cesses of  the  upper  maxillary  bones;  where  a bony 
prominence  is  formed,  to  which  it  is  firmly  united. 
The  upper  part  of  the  anterior  edge  of  this  carti- 
lage, which  is  in  contact  with  the  ossa  nasi,  is  fiat, 
and  is  continued  into  two  lateral  portions  that  are 
extended  from  it,  one  on  each  side,  and  form  a part 
of  the  nose : these  lateral  portions  are  sometimes  spo- 
ken of  as  distinct  cartilages:  but  they  are  really  con- 
tinuations of  the  middle  portion  or  septum.  ^ 

Below  the  lower  edge  of  these  lateral  portums  are 
situated  the  cartilages  which  form  the  orifices  of  the 
nose,  or  the  nostrils.  Of  these,  there  is  one  of  con- 
siderable size,  and  several  small  fragments,  on  each 
side  of  the  septum.  Each  of  the  larger  cartilages 
forms  a portion  of  an  oval  ring,  which  is  placed  ob- 
liquely on  the  side  of  the  septum:  so  that  the  extre- 


3 


Of  the  Nose. 

jmty  of  the  oval  points  downward  and  forward,  while 
the  middle  part  of  the  oval  is  directed  upwards  and 
backwards.  The  sides  of  this  cartilage  are  flat,  and 
unequal  in  breadth.  The  narrowest  side  is  internal, 
and  projects  lower  down  than  the  cartilaginous  sep- 
tum ; so  that  it  is  applied  to  its  fellow  of  the  other 
nostril.  The  external  side  is  broader,  and  continues 
backward  and  upward  to  a considerable  distance. 

The  upper  and  posterior  part  of  this  oval  ring  is 
deficient;  but  the  remainder  of  the  nostril  consists 
of  several  small  pieces  of  cartilage,  which  are  fixed 
in  a ligamentous  membrane  that  is  connected  by  each 
of  its  extremities  to  the  oval  cartilage,  and  thus  com- 
pletes the  orifice. 

The  anterior  parts  of  the  oval  cartilages  form  the 
point  of  the  nose  ; and  the  ligamentous  portions,  the 
alae  or  lateral  parts  of  the  nostrils. 

When  the  external  integuments  and  muscles  are 
removed  from  the  lower  portion  of  the  nose,  so  that 
the  internal  membrane  and  these  cartilages  only  re- 
main, the  internal  membrane  will  be  found  attached 
to  the  whole  bony  margin  of  each  orifice,  and  to  each 
side  of  the  whole  anterior  edge  of  the  middle  carti- 
lage, which  projects  beyond  the  bones.  This  mem- 
brane is  afterwards  continued  so  as  to  line  the  oval 
cartilages  and  the  elastic  membrane  of  the  ala  nasi, 
to  the  margin  of  the  orifice  of  the  nostril. 

The  internal  portions  of  the  oval  cartilages  being 
situated  without  the  septum,  and  applied  to  each 
other,  they  form  the  eternal  edge  of  the  partition 
between  the  nostrils,  or  the  columna  nasi ; which  is 
very  moveable  upon  the  edge  of  the  middle  carti- 
lage. 

The  orifices  of  the  nostrils,  thus  constructed,  are 
dilated  by  that  portion  of  the  muscle,  called  Levator 
Labii  Superior  is  Alseque  Nasi , which  is  inserted 
into  the  alas  nasi. 


4 


Of  the  Cavities  of  the  JYose. 

They  are  drawn  down  by  the  depressor  labii  supe- 
rioris  alaeque  nasi.  They  are  pressed  against  the  sep- 
tum and  the  nose  by  the  muscle  called  Compressor 
JYaris , which  has  however  an  opposite  effect  when 
its  upper  extremity  is  drawn  upwards  by  those  fibres 
of  the  occipito-frontalis,  which  descend  upon  the 
nose,  and  are  in  contact  with  it. 

The  end  of  the  nose  is  also  occasionally  drawn 
down,  by  some  muscular  fibres  which  descend  from 
it,  on  the  septum  of  the  nose,  to  the  orbicularis  oris : 
they  are  considered  as  a portion  of  this  muscle  by 
many  anatomists,  but  were  described  by  Albinus  as 
a separate  muscle,  and  called  JYasalis  Lahii  Supe - 
rioris. 

When  inspiration  takes  place  with  great  force,  the 
alse  nasi  would  be  pressed  against  the  septum  if  they 
were  not  drawn  out  and  dilated  by  some  of  the  mus- 
cles above  mentioned. 

SECTION  II. 

Of  the  Cavities  of  the  JYose. 

To  the  description  of  the  osseous  parts  of  the  nasal 
cavities  in  vol.  I.  page  64,  it  ought  now  to  be  added 
that  the  vacuity  in  the  anterior  part  of  the  osseous 
septum  is  filled  up  by  a cartilaginous  plate,  connect- 
ed with  the  nasal  lamella  of  the  ethmoid  bone  above, 
and  with  the  vomer  below.  This  plate  sends  off 
those  lateral  portions  already  described,  which  form 
the  cartilaginous  part  of  the  bridge  of  the  nose. 

It  should  also  be  observed  that  at  the  back  parts 
of  these  cavities  are  two  orifices  called  the  Posterior 
JYares,  which  are  formed  by  the  palate  bones,  the 
vomer,  and  the  body  of  the  sphenoidal  bone,  and 
are  somewhat  oval. 

The  nasal  cavities,  thus  constructed,  are  lined  by 
a peculiar  membrane,  which  is  called  pituitary  front 


Schneiderian  Membrane.  5 

its  secretion  of  mucus,  or  Schneiderian  after  an  ana- 
tomist who  described  it  with  accuracy.* 

This  membrane  is  very  thick  and  strong,  and 
abounds  with  so  many  blood  vessels,  that  in  the  liv- 
ing subject  it  is  of  a red  colour.  It  adheres  to  the 
bones  and  septum  of  the  nose  like  the  periosteum, 
but  separates  from  them  more  easily.  The  surface 
which  adheres  to  the  bones  has  some  resemblance  to 
periosteum  ; while  the  other  surface  is  soft,  spongy, 
and  rather  villous.  Bichat  seems  to  have  considered 
this  membrane  as  formed  of  two  lamina,  viz.  perios- 
teum, and  the  proper  mucous  membrane  ; but  he 
adds,  that  it  is  almost  impossible  to  separate  them. 

It  has  been  supposed  that  many  distinct  glandular 
bodies  were  to  be  seen  in  the  structure  of  this  mem- 
brane by  examining  the  surface  next  to  the  bones  ;f 
but  this  opinion  is  adopted  by  very  few  of  the  anato- 
mists of  the  present  day.  The  texture  of  the  mem- 
brane appears  to  be  uniform  ; and  on  its  surface  are 
a great  number  of  follicles  of  various  sizes,  from 
which  flows  the  mucous  of  the  nose. 

These  follicles  appear  like  pits,  made  by  pushing 
a pin  obliquely  into  a surface  which  retains  the  form 
of  the  impression.  They  can  be  seen  very  distinctly 
with  a common  magnifying  glass  when  the  membrane 
is  immersed  in  water,  both  on  the  septum  and  on  the 
opposite  surface.  They  are  scattered  over  the  mem- 
brane without  order  or  regularity,  except  that  in  a 
few  places  they  occur  so  as  to  form  lines  of  various 
lengths,  from  half  an  inch  to  an  inch.  The  largest 
of  them  are  in  the  lower  parts  of  the  cavities. 

It  may  be  presumed  that  the  secretion  of  mucous  is 
effected  here  by  vessels  which  are  mere  continuations 
of  arteries  spread  upon  a surface  analogous  to  the 

* Conrad  .Schneider,  a German  professor,  in  a large  work,  “ De  Ca- 
tarrhis,”  published  about  1660. 
t See  Winslow,  section  X-  No.  331/, 


6 


Olfactory  JVerves, 

exhalents,  and  not  convoluted  in  circumscribed 
masses,  as  in  the  case  of  ordinary  glands. 

The  arteries  of  this  membrane  are  derived  from 
various  sources  : the  most  important  of  them  is  the 
nasal  branch  of  the  internal  maxillary,  which  passes 
into  the  nose  through  the  spheno-palatine  foramen, 
and  is  therefore  called  the  Spheno  palatine  Jlrtery. 
It  divides  into  several  twigs,  which  are  spent  upon 
the  different  parts  of  the  surface  of  the  nasal  cavities. 
Two  of  them  are  generally  found  on  the  septum  of 
the  nose  : one,  which  is  small,  passes  forwards  near 
the  middle  ; the  other,  which  is  much  larger,  is  near 
the  lower  part  of  it. 

Two  small  arteries  called  the  anterior  and  poste- 
rior ethmoidal,  which  are  branches  of  the  ophthal- 
mic, enter  the  nose  by  foramina  of  the  cribriform 
plate  of  the  ethmoidal  bone.  These  arteries  pass 
from  the  orbit  to  the  cavity  of  the  cranium,  and  then 
through  the  cribriform  plate  to  the  nose.  In  addi- 
tion to  these,  there  are  some  small  arteries  derived 
from  the  infra  orbital,  the  alveolar  and  the  palatine, 
which  extend  to  the  Schneiderian  membrane  ; but 
they  are  not  of  much  importance. 

The  veins  of  the  nose  correspond  with  the  arteries. 
Those  which  accompany  the  ethmoidal  arteries  open 
into  the  ocular  vein  of  the  orbit,  which  terminates  in 
the  cavernous  sinuses  of  the  head.  The  other  veins 
ultimately  terminate  in  the  external  jugulars. 

The  nerves  of  the  nose  form  an  important  part  of 
the  structure  ; they  are  derived  from  several  sources  ; 
but  the  most  important  branches  are  those  of  the  ol- 
factory. 

The  olfactory  nerves  form  oblong  bulbs,  which  lie 
on  each  side  of  the  crista  galli,  on  the  depressed  por- 
tions of  the  cribriform  plate  of  the  ethmoid  bone, 
within  the  dura  mater.  These  bulbs  are  of  a soft  con- 
sistence, and  resemble  the  cortical  part  of  the  brain 


Olfactory  Nerves.  7 

mixed  with  streaks  of  medullary  matter.  They  send 
off  numerous  filaments,  which  pass  through  the  fora- 
mina of  the  ethmoid  bone,  and  receive  a coat  from 
the  dura  mater  as  they  pass  through  it. 

These  filaments  are  so  arranged  that  they  form  two 
rows,  one  running  near  to  the  septum,  and  the  other 
to  the  surface  of  the  cellular  part  of  the  ethmoid  bone, 
and  the  os  turbinatum : and  in  addition  to  these  are 
some  intermediate  filaments. 

When  the  Schneiderian  membrane  is  peeled  from 
the  bones  to  which  it  is  attached,  these  nervous  fila- 
ments are  seen  passing  from  the  foramina  of  the  eth- 
moid bone  to  the  attached  surfaces  : one  row  passing 
upon  that  which  covered  the  septum,  and  the  other 
to  that  of  the  opposite  side  ; while  the  intermediate 
filaments  take  an  anterior  direction,  but  unite  to  the 
membrane  as  soon  as  they  come  in  contact  with  it. 

All  of  these  can  be  traced  downwards  on  the  afore- 
said surfaces  of  the  membrane  for  a considerable  dis- 
tance, when  they  gradually  sink  into  the  substance  of 
the  membrane,  and  most  probably  terminate  on  the 
internal  villous  surface ; but  they  have  not  been  traced 
to  their  ultimate  termination.  They  ramify  so  that 
the  branches  form  very  acute  angles  with  each  other. 
On  the  septum  the  different  branches  are  arranged  so 
as  to  form  brushes,  which  lie  in  contact  with  each 
other.  On  the  opposite  sides,  the  different  ramifica- 
tions unite  so  as  to  form  a plexus. 

Dr.  Soemmering  published  last  year  some  very 
elegant  engravings  of  the  nose,  representing  one  of 
his  dissections,  which  appears  to  have  been  uncom- 
monly minute  and  successful.*  These  represent  the 
ramifications  as  becoming  more  expanded  and  deli- 
cate in  the  progress  towards  their  terminations,  and 


They  are  entitled,  leones  organovum  liumanoruin  olfactws. 


S Sphenopalatine  and  other  Nerves  of  the  Nose. 

as  observing  a tortuous  course,  with  very  short  mean- 
dering flexures. 

It  is  to  be  observed  that  the  i*am ideations  of  the 
olfactory  nerve,  thus  arranged,  do  not  extend  to  die 
bottom  of  the  cavity.  On  the  external  side,  they  are 
not  traced  lower  than  the  lower  edge  of  the  ethmoid, 
or  of  the  superior  spongy  bone  : and  on  the  septum, 
they  do  not  extend  to  the  bottom,  although  they  are 
lower  than  on  the  opposite  side.  On  the  parts  of  the 
membrane  not  occupied  by  the  branches  of  the  olfac- 
tory nerves,  several  other  nerves  can  be  traced.  The 
nasal  twig  of  the  ophthalmic  branch  of  the  fifth  pair, 
after  passing  from  the  orbit  into  the  cavity  of  the 
cranium,  proceeds  to  the  nasal  cavity  on  each  side 
by  a foramen  of  the  cribriform  plate  ; and  after  send- 
ing off  some  fibrillse,  descends  upon  the  anterior  part 
of  the  septum  to  the  point  of  the  nose.  The  sphe- 
no-palatine  nerve,  which  is  derived  from  the  second 
branch  of  the  fifth  pair,  and  enters  the  nose  by  the 
spheno-palatine  foramen,  is  spread  upon  the  lower 
part  of  the  septum  and  of  the  opposite  side  of  the 
nose  also,  and  transmits  a branch  through  a canal  in 
the  foramen  incisivum  to  the  mouth.  Several  small 
branches  also  pass  to  the  nose  from  the  palatine  and 
other  nerves  ; but  those  already  mentioned  are  the 
most  important. 

A question  has  been  proposed,  whether  the  olfac- 
tory nerve  is  exclusively  concerned  in  the  function 
of  smelling,  or  whether  the  other  nerves  above  men- 
tioned are  also  concerned  in  it.  It  seems  probable 
that  this  function  is  exclusively  performed  by  the 
olfactory  nerve,  and  that  the  other  nerves  are  like 
the  ophthalmic  branch  of  the  fifth  pair,  with  respect 
to  the  optic  nerve.  In  proof  of  this,  it  is  asserted 
that  the  sense  of  smelling  has  entirely  ceased  in  some 
cases,  where  the  sensibility  to  mechanical  irritation 
of  every  kind  has  remained  unchanged.  If  the  ol- 


9 


Extent  of  the  Schneiderian  Membrane. 

factory  nerve  alone  is  concerned  in  the  function  of 
smelling,  it  follows,  that  this  function  must  be  confin- 
ed to  the  upper  parts  of  the  nasal  cavities  ; but  it 
ought  to  be  remembered,  that  the  structure  of  the 
Schneiderian  membrane,  in  the  lower  parts  of  these 
cavities,  appears  exactly  like  that  which  is  above. 

The  surface  of  the  nasal  cavities  and  their  septum, 
when  covered  with  the  Schneiderian  membrane,  cor- 
responds with  the  osseous  surface  formerly  descri- 
bed. The  membrane  covers  the  bones  and  cartilage 
of  the  septum,  so  as  to  make  one  uniform  regular 
surface.  From  the  upper  part  of  the  septum,  it  is 
continued  to  the  under  side  of  the  cribriform  plate 
of  the  ethmoid,  and  lines  it ; the  filaments  of  the 
olfactory  nerve  passing  through  the  foramina  of  that 
bone  into  the  fibrous  surface  of  the  membrane.  It 
is  continued  from  the  septum,  and  from  the  cribri- 
form plate,  to  the  internal  surface  of  the  external 
nose,  and  lines  it.  It  is  also  continued  backwards  to 
the  anterior  surface  of  the  body  of  the  sphenoidal 
bone  ; and,  passing  through  the  foramina  or  openings 
of  the  sphenoidal  cells,  it  lines  these  cavities  com- 
pletely ; but  in  these,  as  well  as  the  other  cavities, 
its  structure  appears  somewhat  changed ; it  becomes 
thinner  and  less  vascular. 

At  the  above  mentioned  foramina,  in  some  subjects, 
it  forms  a plait  or  fold,  which  diminishes  the  aper- 
ture considerably. 

From  the  upper  surface  of  the  nasal  cavities,  the 
membrane  is  continued  downwards  over  the  surface 
opposite  to  the  septum.  On  the  upper  flat  surfaces 
of  the  cellular  portions  of  the  ethmoid,  it  forms  a 
smooth  uniform  surface.  After  passing  over  the  first 
turbinated  bone,  or  that  called  after  Morgagni,  it  is 
reflected  into  the  groove,  or  upper  meatus,  immedi- 
ately within  and  under  it ; the  fold  formed  by  the 
membrane,  as  it  is  reflected  into  the  meatus,  is  rather 
Vol,  ii.  2 


10  Distribution  of  the  Schneiderian  Membrane . 

larger  than  the  bone : and  the  edge  of  the  fold  there- 
fore extends  lower  done  than  the  edge  of  the  bone, 
and  partly  covers  the  meatus  like  a flap,  consisting 
only  of  the  doubled  membrane.  This  fold  generally 
continues  backwards  as  far  as  the  spheno-maxillary 
foramen,  which  it  closes;  the  periosteum,  exterior  to 
the  foramen,  passing  through  it,  and  blending  itself 
with  the  fibrous  surface  of  the  Schneide:ian  mem- 
brane within.  Here  the  spheno-palatine  nerves  and 
arteries  join  the  membrane.  Below  this  meatus,  it 
extends  over  the  middle,  (formerly  called  the  upper,) 
turbinated  bone,  and  is  reflected  or  folded  inwards 
on  the  under  side  of  this  bone,  and  continued  into 
the  middle  meatue  below  it.  In  the  middle  meatus, 
which  is  partly  covered  by  the  last-mentioned  turbi- 
nated bone,  there  are  two  foramina:  one  communi- 
cating with  the  maxillary  sinus ; and  the  other  with 
the  anterior  cells  of  the  ethmoid  and  the  frontal  si- 
nuses. The  aperture  into  the  maxillary  sinuses  is 
much  less  in  the  recent  head,  in  which  th  Schnei- 
derian membrane  lines  the  nose,  than  it  is  in  the 
bare  bones.  A portion  of  the  aperture  in  the  bones 
is  closed  by  the  Schneiderian  membrane,  which  is 
extended  over  it : the  remainder  of  the  aperture  is 
unclosed ; and  through  this  foramen,  the  membrane 
is  reflected  so  as  to  line  the  whole  cavity.  As  a por- 
tion of  the  foramen  is  covered  by  the  membrane,  and 
this  portion  as  well  as  the  other  parts  of  the  cavity 
is  lined  by  the  membrane,  it  is  obvious  that  at  the 
place  where  the  membrane  is  extended  over  the 
foramen  in  the  bone,  it  must  be  doubled  ; or,  in 
other  words,  a part  of  the  aperture  of  the  maxillary 
sinus  is  closed  by  a fold  of  the  Schneiderian  mem- 
brane. 

This  aperture  varies  in  size  in  different  subjects, 
and  is  often  equal  in  diameter  to  a common  quill.  It 
is  situated  in  the  middle  of  the  meatus,  and  is  covered 


Eustachian  Tube. 


11 


by  the  middle  turbinated  bone : immediately  above  it, 
is  a prominence  of  the  cellular  structure  of  the  eth- 
moid bone,  which  has  a curved  or  semicircular  figure. 
Near  this  prominence,  in  the  same  meatus,  a groove 
terminates,  which  leads  from  the  anterior  ethmoid 
cells  and  the  frontal  sinuses. 

From  the  middle  meatus,  the  membrane  proceeds 
over  the  inferior  turbinated  bone,  and  is  reflected 
round  and  under  it  into  the  lower  meatus.  It  appears 
rather  larger  than  the  bone  which  it  covers;  and 
therefore  the  lower  edge  of  the  bone  does  not  extend 
so  low  as  the  lower  edge  of  the  membrane,  which  of 
course  is  like  a fold  or  plait.  The  membrane  then 
continues  and  lines  the  lower  meaiuos  here  it  appears 
less  full  than  it  is  in  the  turbinated  bone.  In  this 
meatus,  near  to  its  anterior  end,  is  the  lower  orifice 
of  the  lachrymal  duct : this  is  simply  lined  by  the 
Schneiderian  membrane,  which  is  continued  into  it, 
and  forms  no  plaits  or  folds  that  affect  the  orifice. 

Orifice  of  the  Eustachian  Tube. 

Immediately  behind  each  of  the  nasal  cavities,  on 
the  external  side,  is  the  orifice  of  the  Eustachian 
Tube.  It  has  an  oval  form,  and  is  large  enough  to 
admit  a very  large  quill.  Its  position  is  oblique; 
the  upper  extremity  being  anterior  to  the  other  parts 
of  the  aperture,  and  on  a line  with  the  middle  mea- 
tus, while  the  centre  is  behind  the  inferior  turbinated 
bone.  The  lower  part  of  the  oval  is  deficient.  This 
tube  is  formed  posteriorly  by  a cartilaginous  plate. 
It  is  lined  by  the  membrane  continued  from  the  nose. 

The  cavities  of  the  nose  answer  a twofold  purpose  in 
the  animal  economy:  they  afford  a surface  for  the 
expansion  of  the  olfactory  nerves : and  a passage 
for  the  external  air  to  the  windpipe,  in  respiration. 

The  function  of  smelling  appears  to  be  dependent,  to 
a certain  degree,  upon  respiration.  It  has  been  as- 


12 


Observations  respecting  the  Nose. 

serted  that  unless  the  air  passes  in  a stream  through 
the  nose,  as  in  respiration,  the  perception  of  odour 
does  not  take  place;  that  in  persons  who  breathe 
through  wounds  and  apertures  in  the  windpipe,  the 
function  of  smelling  is  not  performed.  It  is  rather 
in  confirmation  of  this  proposition,  that  most  per- 
sons, when  they  wish  to  have  an  accurate  perception 
of  any  odour,  draw  in  air  rapidly  through  the  nose. 

Although  the  ultimate  terminations  of  the  olfactory 
nerves  cannot  be  demonstiated  like  those  of  the  op- 
tic and  auditory  nerves,  it  is  probable,  from  the  ap- 
pearance of  the  fibres,  while  they  are  distinguisha- 
ble, that  they  are  finally  arranged  with  great  delica- 
cy. It  is  certain  that  the  impressions  from  whence 
we  derive  the  perceptions  of  many  odours  must  be 
very  slight;  as  odorous  bodies  will  impregnate 

the  aii  of  a large  chamber  for  a great  length  of  time, 
without  losing  any  sensible  weight. 

With  respect  to  delicacy  of  structure  and  sensibility, 
it  is  probable  that  the  nose  holds  a middle  rank  be- 
tween the  eye  or  ear,  and  the  tongue  : and  on  this 
account  the  mucous  is  necessary  as  a covering  and 
defence  of  its  surface. 

It  has  been  ascertained,  by  the  investigations  of  che- 
mists, that  this  mucous  contains  the  same  ingredi- 
ents as  the  tears  already  described,  viz.  animal  mu- 
cous and  water;  with  muriate  of  soda,  and  soda  un- 
combined; phosphate  of  lime,  and  phosphate  of  soda. 

The  animal  mucous,  which  is  a most  important  ingre- 
dient in  the  composition,  resembles  the  mucilage 
formed  by  some  of  the  vegetable  gums  in  several 
particulars  ; and  differs  from  them  in  others. 

The  mucous  of  the  nose,  if  it  remain  there  long  after 
it  is  secreted,  becomes  much  more  viscid  in  con- 
sistence, and  changes  from  a whitish  colour  to  one 
which  partakes  more  or  less  of  the  yellow.  It  is 
probable  that  an  incipient  putrefaction  may  occasion 
these  changes  in  it. 

The  use  of  the  frontal,  maxillary  and  other  sinuses, 
communicating  with  the  nose,  has  been  the  subject 
of  some  inquiry.  As  there  can  be  no  stream  of  air 
through  them,  and  as  the  membrane  lining  them  is 
neither  so  thick,  villous  nor  flexible  as  that  lining 
the  nose,  it  may  be  concluded,  a priori,  that  they 
are  not  concerned  in  the  function  of  smelling.  This 


13 


Use  of  the  Sinuses  of  the  Nose, 

opinion  is  strengthened  by  the  fact,  that  very  young 
children,  in  whom  these  sinuses  scarcely  exist,  en- 
joy the  sense  of  smelling  in  perfection.  The  fol- 
lowing fact  is  also  in  support  of  it.  The  celebrated 
Desault  attended  a patient,  in  whom  one  of  the 
frontal  sinuses  was  laid  open  by  the  destruction  of 
the  bone  which  covered  it  anteriorly.  This  patient 
was  able  to  breathe  a short  time  through  the  sinus 
when  the  mouth  and  nose  were  closed  : At  the  re- 
quest of  Desault  he  breathed  in  this  manner  when 
a cup  of  some  aromatic  liquor  was  held  near  the 
opening  of  the  sinus  : and  had  not  the  least  percep- 
tion of  odour.  This  experiment  was  repeated  se- 
veral times. 

Many  physiologists  believe  that  these  sinuses  have  an 
effect  in  modulating  the  voice. 


CHAPTER  II. 


OF  THE  MOUTH. 

The  general  cavity  of  the  mouth  is  formed  ante- 
riorly and  laterally  by  the  connexion  of  the  lips  and 
cheeks  to  the  upper  and  lower  jaws  : so  that  the  teeth 
and  the  alveoli  of  both  jaws  may  be  considered  as 
within  the  cavity.  Above,  it  is  bounded  principally 
by  the  palatine  processes  of  the  upper  maxillary  and 
palate  bones,  and  the  soft  palate,  which  continues 
backward  from  them  in  the  same  direction. 

Below,  the  cavity  is  completed  by  several  muscles, 
which  proceed  from  almost  the  whole  internal  circum- 
ference of  the  lower  jaw,  and,  by  their  connexions 
with  each  other,  with  the  tongue  and  the  os  hyoides, 
form  a floor  or  bottom  to  it.  The  tongue  is  particular- 
ly connected  to  this  surface,  and  may  be  considered 
as  resting  upon  and  supported  by  it. 

To  acquire  an  idea  of  the  parietes  of  this  cavity, 
after  studying  the  upper  and  lower  maxillary  bones, 
the  orbicularis  oris  and  the  muscles  connected  with  it, 
especially  the  buccinator,  ought  to  be  examined  ; and 
also  the  digastricus,  the  mvlo-hyoideus,  genio-hyoi- 
deus,  and  genio-hyoglossus.  By  this  it  will  appear 
that  the  lips  and  cheeks,  and  the  basis  or  floor  of  the 
mouth,  are  formed  in  a great  measure  by  muscles. 
Upon  the  internal  surface  of  these  muscles,  a por- 
tion of  cellular  and  adipose  substance  is  arranged, 
as  well  as  glandular  bodies  of  different  sizes  ; and  to 
these  is  attached  the  membrane  which  lines  the  in- 
side of  the  mouth. 

This  membrane  passes  from  the  skin  of  the  face 
to  the  lips,  and  the  inside  of  the  mouth;  and,  al- 
though it  is  really  a continuation  of  the  skin,  there 


Internal  Surface  of  the  Mouth.  15 

is  so  great  a change  of  structure,  that  it  ought  to  be 
considered  as  a different  membrane.  At  the  orifice 
of  the  lips  it  is  extremely  thin,  and  so  vascular  that 
it  produces  the  fine  florid  colour  which  appears  there 
in  health.  It  is  covered  by  a cuticle,  called  by  some 
anatomists,  Epithelium , which  has  a proportionate 
degree  of  delicacy,  and  can  be  separated  like  the 
cuticle  in  other  parts.  When  this  cuticle  is  separa- 
ted, the  lips  and  the  membrane  of  the  mouth  appear 
to  be  covered  with  very  fine  villi,  which  are  parti- 
cularly apparent  in  some  preparations  of  the  lips  af- 
ter injection  and  maceration.* 

Under  this  membrane  are  many  small  glandular 
bodies' of  a roundish  form,  called  glandulse  labiales, 
whose  excretory  ducts  pass  through  it  to  the  inner 
surface  of  the  mouth,  for  the  purpose  of  lubrifying 
it  withjjieir  secretion,  which  is  mingled  with  the 
saliva. 

The  membrane,  which  lines  the  inside  of  the  lips 
and  cheeks,  is  somewhat  different  from  that  which 
forms  the  surface  of  the  orifice  of  the  mouth  : it  is 
not  so  florid  ; the  blood  vessels  in  its  texture  are 
larger  and  not  so  numerous.  This  change,  however, 
takes  place  very  gradually,  in  the  progress  of  the 
membrane,  from  the  orifice  of  the  lips  to  the  back 
part  of  the  cheeks.  Glandular  bodies,  like  those  of 
the  lips,  are  situated  immediately  exterior  to  this 
membrane  of  the  cheeks,  between  it  and  the  mus- 
cles : their  ducts  open  on  its  surface.  These  glands 
are  called  Buccales. 

This  lining  membrane  is  continued  from  the  inter- 
nal surface  of  the  lips  and  cheeks  to  the  alveolar  por- 
tions of  the  upper  and  lower  jaws,  which  are  in  the 
cavity  of  the  mouth,  and  covers  them,  adhering 
firmly  to  the  periosteum. 

* Ruysch  had  a fine  preparation  of  this  structure.  See  Thesaurus  VII. 
Tab.  III.  Fig.  5. 


16  Gums. — Surface  of  the  Hard  Palate. 

The  teeth  appear  to  have  passed  through  aper- 
tures in  this  membrane,  and  are  surrounded  by  it 
closely  at  their  respective  necks. 

The  portion  of  membrane,  which  thus  invests  the 
jaws,  constitutes  the  gums;  which  have  now  acquired 
a texture  very  different  from  that  of  the  membrane, 
from  which  they  were  continued.  They  are  ex- 
tremely firm  and  dense,  and  very  vascular.  It  is 
probable  that  their  ultimate  structure  is  not  perfect- 
ly understood. 

In  the  desease  called  scurvy , they  tumify  and  lose 
the  firmness  of  their  texture ; they  acquire  a livid 
colour,  and  are  much  disposed  to  hemorrhage. 

From  the  alveoli  of  the  upper  jaw,  the  lining 
membrane  is  continued  upon  the  palatine  processes 
of  the  upper  maxillary  and  palate  bones,  or  the  roof 
of  the  mouth. 

This  membrane  of  the  palate  is  not  quite  so  firm  as 
that  of  the  gums,  and  is  also  less  florid  : it  adheres 
firmly  to  the  periosteum,  and  thus  is  closely  fixed  to 
the  bones.  There  is  generally  a ridge  on  its  surface, 
immediately  under  thesature  between  the  two  upper 
maxillary  bones ; and  some  transverse  ridges  are  also 
to  be  seen  upon  it.  On  the  internal  surface  of  this 
membrane  are  small  glandular  bodies,  whose  ducts 
open  on  the  surface  of  the  palate. 

It  is  asserted,  that  this  membrane  has  a limited  de- 
gree of  that  sensibility  which  is  essential  to  the  func- 
tion of  tasting  ; and,  that  if  certain  sapid  substances 
are  carefully  applied  to  it,  their  respective  tastes  will 
be  perceived,  although  they  have  not  been  in  contact 
with  the  tongue. 

The  membrane  is  continued  from  the  bones  above 
mentioned  to  the  soft  palate,  or  velum  pendulum  pa- 
lati,  which  is  situated  immediately  behind  them.  This 
soft  palate  may  be  considered  as  a continuation  of 
the  partition  between  the  nose  and  mouth ; it  is  at- 


17 


Soft  Palate.--  Uvula. 

tached  to  the  posterior  edge  of  the  palatine  processes 
of  the  ossa  palati,  and  to  the  pterygoid  processes  of 
the  sphenoidal  bone.  Its  interior  structure  is  mus- 
cular. The  upper  surface  is  covered  by  the  mem- 
brane of  the  nose,  the  lower  surface  by  the  mem- 
brane which  lines  the  month. 

The  muscles,  which  contribute  to  the  composition 
of  this  structure,  are  the  circumflexi  and  the  le- 
vatores  palati  above,  and  the  constrictores  isthmi 
faucium  and  palato-pharyngei  below.  (See  Vol.  I. 
page  190 — 191.)  Thus  composed  the  soft  palate 
constitutes  the  back  part  of  the  partition  between 
the  nose  and  mouth.  When  viewed  from  before, 
with  the  mouth  open,  it  presents  towards  the  tongue 
an  arched  surface,  which  continues  downwards  on 
each  side,  until  it  comes  nearly  in  contact  with  the 
edges  of  that  organ.  On  each  of  the  lateral  parts  of 
this  arch,  are  two  pillars,  or  rather  prominent  ridges, 
which  project  into  the  mouth.  These  ridges  are  at 
some  distance  from  each  other  below,  and  approach 
much  nearer  above,  so  that  they  include  a triangular 
space.  They  are  called  the  lateral  half  arches  of 
the  palate.  Each  of  them  is  formed  by  a plait  or 
fold  of  the  lining  membrane  of  the  mouth,  and  contains 
one  of  the  two  last  mentioned  muscles  : the  anterior, 
the  constrictor  isthmi  faucium  ; the  posterior,  the  pa- 
lato-pharyngeus.^Tk<se  muscles,  of  course,  draw  the 
palate  down  toward  the  tongue  when  they  contract. 

From  the  centre  of  the  arch,  near  its  posterior 
edge,  is  suspended  the  uvula,  a conical  body,  which 
varies  in  length  from  less  than  half  an  inch  to  rather 
more  than  one  inch.  It  is  connected  by  its  basis  to 
the  palate  ; but  its  apex  is  loose  and  pendulous. 
This  body  is  covered  by  the  lining  membrane  of  the 
mouth.  It  contains  many  small  glands,  and  a mus- 
cle also,  the  azygos  uvulse,  which  arises  from  the 
posterior  edge  of  the  ossa  palati,  at  the  suture  which 

Vol.  ii,  3 


18 


The  Tongue. 

connects  them  to  each  other,  and,  passing  posteriorly 
upon  the  soft  palate,  extends  from  the  basis  to  the 
apex  of  the  uvula,  into  which  it  is  inserted.  By  the 
action  of  this  muscle,  the  length  of  the  uvula  can  be 
very  much  diminished  ; and  when  its  contraction 
ceases,  that  body  is  elongated. 

The  pendulous  part  of  the  uvula  can  also  be  moved, 
in  certain  cases,  to  either  side. 

It  is  commonly  supposed,  that  the  principal  use  of 
this  little  organ  is  to  modulate  the  voice  ; but  there 
are  good  reasons  for  believing,  that  it  has  another 
object.  It  was  remarked  by  Fallopius,  (and  the  ob- 
servation has  been  confirmed  by  many  surgeons  since 
his  time,)  that  the  uvula  may  be  removed  completely 
without  occasioning  any  alteration  of  the  voice,  or 
any  difficulty  of  deglutition,  if  the  soft  palate  be  left 
entire. 

The  soft  palate  is  so  flexible,  that  it  yields  to  the 
actions  of  the  levatores  palati,  which  draw  it  up  so 
as  to  close  the  posterior  nares  completely. 

It  also  yields  to  the  circumflexi  or  tensores,  which 
stretch  it  so  as  to  do  away  its  arched  appearance. 

It  is  therefore  very  properly  called  the  Palatum 
Molle.  It  is  also  frequently  called  the  Velum  Pen- 
dulum palati , from  the  position  which  it  assumes. 

The  Tongue , 

Which  is  a very  important  part  of  this  structure, 
is  retained  in  its  position  and  connected  with  the 
parts  adjoining  it,  by  the  following  arrangements. 

The  os  hyoides,  which  as  its  name  imports,  re- 
sembles the  Greek  letter  v,  or  half  an  oval,  is  situa- 
ted rather  below  the  angles  of  the  lower  jaw,  in  the 
middle  of  the  upper  part  of  the  neck.  It  is  retained 
in  its  position  by  the  sterno-hyoidei  muscles,  which 
connect  it  to  the  upper  part  of  the  sternum  ; by  the 
coraco-hyoidei,  w’hich  pass  to  it  obliquely  from  the 


19 


Structure  of  the  Tongue. 

scapula ; by  the  thyro-hyoidei,  which  pass  to  it  di- 
rectly upward  from  the  thyroid  cartilage:  all  of 
which  connect  it  to  parts  below.  To  these  should  be 
added  the  stylo-hyoidei,  which  pass  to  it  obliquely 
from  behind  and  rather  from  above ; the  mylo-hyoidei, 
which  come  rather  anteriorly  from  the  lateral  parts 
of  the  lower  jaw  ; and  the  genio-hyoidei,  which  arise 
from  a situation  directly  anterior  and  superior,  the 
chin.  When  these  muscles  are  at  rest,  the  situation 
of  the  os  hyoides  is,  as  above  described,  below  the 
angles  of  the  lower  jaw  : when  those,  in  one  parti- 
cular direction,  act  while  the  others  are  passive,  the 
bone  may  be  moved  upwards  or  downwards,  back- 
wards or  forwards,  or  to  either  side.  This  bone  may 
be  considered  as  the  basis  of  the  tongue  ; for  the  pos- 
terior extremity  of  that  organ  is  attached  to  it ; and 
of  course  the  movements  of  the  bone  must  have  an 
immediate  effect  upon  those  of  the  tongue. 

The  tongue  is  a fiat  body  of  an  oval  figure,  but 
subject  to  considerable  changes  of  form. 

The  posterior  extremity,  connected  to  the  os  hy- 
oides, is  commonly  called  its  basis ; the  anterior  ex- 
tremity, which,  when  the  tongue  is  quiescent,  is 
rather  more  acute,  is  called  its  apex. 

The  lower  surface  of  the  tongue  is  connected  with 
a number  of  muscles,  which  are  continued  into  its 
substance.  This  connexion  is  such,  that  the  edges  of 
the  tongue  are  perfectly  free  and  unconnected  ; and  so 
is  the  anterior  extremity  for  a considerable  distance 
from  the  apex  towards  the  base. 

The  substance  of  the  tongue  consists  principally  of 
muscular  fibres  intermixed  with  a delicate  adipose 
substance.  It  is  connected  to  the  os  hyoides  by  the 
hyoglossus  muscle  and  also  by  some  other  muscular 
fibres,  as  well  as  by  a dense  membranous  substance, 
which  appears  to  perform  the  part  of  a ligament. 


20 


Structure  of  the  Tongue. 

This  connexion  is  also  strengthed  by  the  continuance 
of  the  integuments  from  the  tongue  to  the  epiglottis 
cartilage,  to  be  hereafter  described  ; for  that  cartil- 
age is  attached  by  ligaments  to  the  os  hyoides. 

The  tongue  is  thin  at  its  commencement  at  the  os 
hyoides  : but  it  soon  increases  in  thickness.  The 
muscular  fibres  in  its  composition  have  been  consider- 
ed as  intrinsic,  or  belonging  wholly  to  its  internal 
structure ; and  extrinsic,  or  existing  in  part  outside 
of  this  structure.  The  linguales  muscles  are  intrin- 
sic : (Vol.  I.  page  189,)  they  are  situated  near  the 
under  surface  of  the  tongue,  one  on  each  side,  sepa- 
rated from  each  other  by  the  genio-hyo-glossi  mus- 
cles, and  extending  from  the  basis  of  the  tongue  to 
its  apex.  These  muscles  can  be  easily  traced  as  above 
described  ; but  there  are  also  many  fibres  in  the 
structure  of  the  tongue,  which  seem  to  pass  in  every 
direction,  and  of  course  are  different  from  those  of 
the  linguales  muscles.  To  these  two  sets  of  fibres 
are  owing  many  of  the  immensely  varied  motions  of 
the  different  parts  of  the  tongue. 

In  addition  to  these,  are  the  extrinsic  muscles,  which 
originate  from  the  neighbouring  parts,  and  are  insert- 
ed and  continued  into  the  substance  of  the  tongue. 

Among  the  most  important  of  these  muscles,  are 
those  which  proceed  from  the  chin,  or  the  genio- 
hyo-glossi.  They  are  in  contact  with  each  other: 
their  fibres  radiate  from  a central  point  on  the  inside 
of  the  chin,  and  are  inserted  into  the  middle  of  the 
lower  surface  of  the  tongue  : the  insertion  commen- 
cing at  a short  distance  from  its  apex,  and  continu- 
ing to  its  base. 

As  the  genio-hyo-glossi  muscles  have  a considera- 
ble degree  of  thickness,  they  add  much  to  the  bulk  of 
the  tongue  in  the  middle  of  the  posterior  parts  of  it. 

The  hyo-glossi  and  the  stylo-glossi,  being  conti- 


21 


Papillse  of  the  Tongue . 

nued  into  the  posterior  and  laternal  parts,  contribute 
also  to  the  bulk  of  these  parts. 

The  tongue,  thus  composed  and  connected,  lies, 
when  at  rest,  on  the  mylo-hyoidei  muscles;  and  the 
space  between  it  and  these  muscles  is  divided  into 
two  lateral  parts  by  the  above  described  genio-hyo- 
glossi.  In  the  space  above  mentioned,  is  a small  sa- 
livary gland,  of  an  irregular  oval  form  ; the  greatest 
diameter  of  which  extends  from  before  backwards, 
and  its  edges  present  outwards  and  inwards.  It  has 
several  excretory  ducts,  the  orifices  of  which  form  a 
line  on  each  side  of  the  tongue.  This  gland  is  very 
prominent  under  the  tongue  ; and  when  the  tongue 
is  raised  it  is  particularly  conspicuous ; it  is  called 
the  Sublingual. 

The  lining  membrane  of  the  mouth  continues  from 
the  inside  of  the  alveoli  of  the  lower  jaw,  which  it 
covers,  over  the  sublingual  glands  to  the  lower  sur- 
face of  the  tongue.  In  this  situation  it  is  remarkably 
thin ; but,  as  it  proceeds  to  the  upper  surface  of  the 
tongue,  its  texture  changes  considerably  ; and  on  this 
surface  it  constitutes  the  organ  of  taste. 

The  upper  surface  of  the  tongue,  although  it  is 
continued  from  the  thin  membrane  above  described, 
is  formed  by  a rough  integument  which  consists,  like 
the  skin,  of  three  lamina.  The  cuticle  is  very  thin; 
and  under  it,  the  rete  raucosum*  is  thicker  and  softer 
than  in  other  places. 

The  true  skin  here  abounds  with  eminences  of  va- 
rious sizes  and  forms,  all  of  which  are  denominated 
Papillse.  The  largest  of  these  are  situated  on  the 
posterior  part  of  the  tongue,  and  are  so  arranged  that 
they  form  an  angle  rather  acute,  with  its  point  back- 

s M.  Bichat  appears  to  have  had  doubts  whether  the  real  rete  tnucosum 
existed  here.  He  says  that  he  could  only  perceive  a decussation  of  vessels 
in  the  intervals  of  the  papillse,  which,  as  he  supposes,  occasioned  the  florid 
colour  of  the  tongue. 


22 


Papillse  of  the  Tongue. 

wards.  They  are  commonly  nine  in  number  : they 
resemble  an  inverted  cone ; or,  are  larger  at  their 
head  than  their  basis.  They  are  situated  in  pits  or 
depressions,  to  the  bottoms  of  which  they  are  con- 
nected. In  many  of  them  there  are  follicles,  or  per- 
forations, which  have  occasioned  them  to  be  regard- 
ed as  glands.  They  are  called  Papillse  Maximse, 
or  Capitatse. 

The  papillas,  next  in  size,  are  denominated  fungi- 
form by  some  anatomists,  and  Medise  or  Semilenti- 
cnlares  by  others.  They  are  nearly  cylindrical  in 
form,  with  their  upper  extremities  regularly  round- 
ed. They  are  scattered  over  the  upper  surface  of 
the  tongue,  in  almost  every  part  of  it,  at  irregular 
distances  from  each  other. 

The  third  class  are  called  conoidal  or  villous. 
They  are  very  numerous,  and  occupy  the  greatest 
part  of  the  surface  of  the  tongue.  Although  they 
are  called  conoidal , there  is  a great  difference  in  their 
form  ; many  of  them  being  irregularly  angular  and 
serrated,  as  well  as  conical. 

Soemmering  and  other  German  anatomists  consider 
the  smallest  papillaj  as  a fourth  class,  which  they  call 
the  filiform  : these  lie  between  the  others. 

It  is  probable  that  these  papillae  are  essential  parts 
of  the  organ  of  taste  ; and  their  structure  is  of  course 
an  interesting  object  of  inquiry. 

The  nerves  of  the  tongue  have  been  traced  to  the 
papillae,  and  have  been  compared  by  some  anatomists 
to  the  stalk  of  the  apple,  while  the  papillse  resembled 
the  fruit ; but  their  ultimate  termination  does  not  ap- 
pear to  have  been  ascertained.* 


' In  the  explanation  of  the  plates,  referred  to  in  the  following  sentence, 
Soemmering  observes,  that  when  the  fibrillae  of  the  lingual  nerve  of  the 
fifth  pair  are  traced  to  the  papillae  of  the  second  class,  they  swell  out  into 
a conical  form  ; and  these  nervous  cones  are  in  such  close  contact  with 
each  other,  that  the  point  of  the  finest  needle  could  not  be  insinuated  into 
the  papillae  without  touching  a nerve. 


Blood  vessels  of  ike  Tongue.  23 

Soemmering  has  lately  published  some  elegant  en- 
graved copies  of  drawings  of  these  papillae,  when 
they  were  magnified  twenty-five  times ; from  which 
it  appears  that  a very  large  number  of  vessels,  parti- 
cularly of  arteries,  exist  in  them.  These  vessels  are 
arranged  in  a serpentine  direction,  and  are  prominent 
on  the  surface ; but  they  appear  doubled,  and  the 
most  prominent  part  is  the  doubled  end. — This  ar- 
rangement of  vessels  is  perceptible  on  the  sides  of 
the  tongue,  as  well  as  on  the  papillae. 

Behind  the  large  papillae  is  a foramen,  first  de- 
scribed by  Morgagni,  and  called  by  him  Foramen 
Csecum.  It  is  the  orifice  of  a cavity  which  is  not 
deep  ; the  excretory  ducts  of  several  mucous  glands 
open  into  it. 

On  the  upper  surface  of  the  tongue,  a groove  is 
often  to  be  seen,  which  is  called  the  linea  mediana , 
and  divides  it  into  two  equal  lateral  parts.  Below, 
the  lining  membrane  of  the  mouth,  as  it  is  continued 
from  the  lower  jaw  to  the  tongue,  forms  a plait, 
which  acts  as  a ligament,  and  is  called  the  frsenum 
linguse.  It  is  attached  to  the  middle  of  the  tongue, 
at  some  distance  behind  the  apex. 

The  tongue  is  Well  supplied  with  blood  vessels, 
which  are  derived  from  the  lingual  branch  of  the 
external  carotid  on  each  side.  This  artery  passes 
from  the  external  carotid,  upwards,  inwards,  and 
forwards,  to  the  body  of  the  tongue.  In  this  course 
it  sends  off  several  small  arteries  to  the  contiguous 
parts,  and  one,  which  is  spent  about  the  epiglottis 
and  the  adjoining  parts,  called  the  Dorsalis  Linguse. 
About  the  anterior  edge  of  the  hyo-glossus  muscle, 
it  divides  into  two  large  branches  : one  of  which, 
called  the  Sublingual,  passes  under  the  tongue  be- 
tween the  genio-hyo-glossus  and  the  sublingual  gland, 
and  extends  near  to  the  symphysis  of  the  upper  jaw ; 
sending  branches  to  the  sublingual  gland,  to  the 


24  Blood  vessels  of  the  Tongue. 

muscles  under  the  tongue,  to  the  skin,  and  the  lower 
lip.  The  other  is  in  the  substance  of  the  tongue, 
on  the  under  side  near  the  surface,  and  extends  to 
the  apex. 

The  veins  of  this  organ  are  not  so  regular  as  the 
arteries : they  communicate  with  the  external  jugu- 
lar ; and  some  of  them  are  always  very  conspicuous 
under  the  tongue  : these  are  called  ranular. 

It  is  to  be  observed,  that  the  vessels  on  each  side 
have  but  little  connexion  with  each  other  ; for  those 
of  one  side  may  be  injected  while  the  others  continue 
empty. 

The  tongue  is  also  well  supplied  with  nerves,  and 
derives  them  from  three  different  sources  on  each 
side,  viz.  from  the  fifth,  the  eighth,  and  ninth  pairs 
of  the  head. 

The  lingual  portion  of  the  third  branch  of  the  fifth 
pair,  passing  under  the  tongue,  enters  its  substance 
about  the  middle,  and  forms  many  minute  branches, 
which  pass  to  the  papillae  of  the  fore  part  of  the 
tongue. 

The  glosso-pharyngeal  portion  of  the  eighth  pair, 
sending  off  several  branches  in  its  course,  passes  to 
the  tongue  near  its  basis,  and  divides  into  many 
small  branches,  which  are  spent  upon  the  sides  and 
middle  of  the  root  of  the  tongue,  and  also  upon  the 
large  papillae. 

The  ninth  pair  of  nerves  are  principally  appro- 
priated to  the  tongue.  They  pass  on  each  side  to 
the  most  fleshy  part  of  it,  and  after  sending  one 
branch  to  the  rnylo-hyoideus,  and  another  to  com- 
municate with  the  lingual  branch  of  the  fifth  pair, 
they  are  spent  principally  upon  the  genio-glossi,  and 
linguales  muscles. 

The  tongue  answers  a threefold  purpose.  It  is 
the  principal  organ  of  taste.  It  is  a very  important 
agent  in  the  articulation  of  words ; and  it  assists  in 


Salivary  Glands , 25 

those  operations  upon  our  food,  which  are  perform- 
ed in  the  mouth. 

The  Salivary  Glands. 

The  salivary  glands  have  such  an  intimate  con- 
nexion with  the  mouth  that  they  may  be  described 
with  it.* 

There  are  three  principal  glands  on  each  side  : 
the  Parotid , the  Submaxillary  and  the  Sublingual. 
They  are  of  a whitish  or  pale  flesh-colour,  and  are 
composed  of  mauv  small  united  masses  of  lobuli, 
each  of  which  sends  a small  excretory  duct  to  join 
similar  ducts  from  the  other  lobuli,  and  thereby  form 
the  great  duct  of  the  gland. 

The  Parotid  is  much  larger  than  the  other  glands. 
It  occupies  a large  portion  of  the  vacuity  between 
the  mastoid  process  and  the  posterior  parts  of  the 
lower  jaw.  It  extends  from  the  ear  and  the  mastoid 
process  over  a portion  of  the  masseter  muscle,  and 
from  the  zygoma  to  the  basis  of  the  lower  jaw.  Its 
name  is  supposed  to  be  derived  from  two  Greek 
words  which  signify  contiguity  to  the  ear.  It  is  of  a 
firm  consistence.  It  receives  branches  from  the  ex- 
ternal carotid  artery  and  from  its  facial  branch. 

From  the  anterior  edge  of  this  gland,  rather  above 
the  middle,  the  great  duct  proceeds  anteriorly  across 
the  masseter  muscle ; and,  after  it  has  passed  over 
it,  bends  inward  through  the  adipose  matter  of  the 
cheek  to  the  buccinator  muscle,  which  it  perforates 
obliquely  and  opens  on  the  inside  of  the  cheek  op- 
posite to  the  interval  between  the  second  and  third 
molar  teeth  of  the  upper  jaw.  The  aperture  of  the 
duct  is  rather  less  than  the  general  diameter  of  it, 
and  this  circumstance  has  the  effect  of  a valve. 
When  the  duct  leaves  the  parotid,  several  small 
glandular  bodies  called  socise  parotidis,  are  often 

For  a general  account  of  glands,  see  the  appendix  to  this  volume 

Vol.  ii.  4 


26  Parotid  and  Submaxillary  Glands. 

attached  to  it,  and  their  ducts  communicate  with  it. 
The  main  duct  is  sometimes  called  after  Steno,  who 
first  described  it. 

When  the  mouth  is  opened  wide,  as  in  gaping, 
there  is  often  a jet  of  saliva  from  it  into  the  mouth. 

The  parotid  gland  furnishes  the  largest  proportion 
of  saliva. 

It  covers  the  nerve  called  Portio  Dura , after  it 
has  emerged  from  the  foramen  stylo- mastoideum. 

The  second  gland  is  called  the  Submaxillary.  It  is 
much  smaller  than  the  parotid,  and  rather  round  in 
form.  It  is  situated  immediately  within  the  angle 
of  the  lower  jaw,  between  it,  on  the  outside,  and  the 
tendon  of  the  digastric  muscle  and  the  ninth  pair  of 
nerves  internally.  Its  posterior  extremity  is  con- 
nected by  cellular  membrane  to  the  parotid  gland  ; 
its  anterior  portion  lies  over  a part  of  the  mylo- 
hyoideus  muscle  ; and  from  it  proceeds  the  excretory 
duct,  which  is  of  considerable  length,  and  passes  be- 
tween the  mylo-hyoideus  and  the  genio-glossus  mus- 
cles along  the  under  and  inner  edge  of  the  sublin- 
gual gland.  In  this  course  the  duct  is  sometimes 
surrounded  with  small  glandular  bodies,  which  seem 
to  be  appendices  of  the  sublingual  gland.  It  termi- 
nates under  the  tongue,  on  the  side  of  the  fraenum 
linguae,  by  a small  orifice  which  sometimes  forms  a 
papilla.* 

The  orifice  is  often  smaller  than  the  duct ; in  con- 
sequence of  which,  obstruction  frequently  occurs  here, 
and  produces  the  disease  called  ranula. 

The  sublingual  gland,  which  has  already  been 
mentioned,  lies  so  that,  when  the  tongue  is  turned 

* Lassus  informs  us  that  Oribases,  afterwards  all  the  Arabians,  and  sub- 
sequently Guy  De  Chauljac,  Lanfranc,  Achillini  Berenger  De  Carpi, 
Charles  Etienne,  Casserius  and  several  others  have  given  the  description 
of  these  salivary  ducts,  notwithstanding  which  Wharton,  a physician  of 
London,  attributed  to  himself  the  discovery  of  them  on  the  bullock  in 
1656.— Ed. 


Sublingual  Gland. — Saliva.  27 

up,  it  can  be  seen  protruding  into  the  cavity  of  the 
mouth,  and  covered  by  the  lining  membrane,  which 
seems  to  keep  it  fixed  in  its  place.  It  lies  upon  the 
mylo-hyoideus,  by  the  side  of  the  genio-hyoideus  ; 
and  is  rather  oval 'in  form  and  flat.  Its  greatest 
length  is  from  before  backwards;  its  position  is  rather 
oblique,  one  edge  being  placed  obliquely  inwards  and 
upwards,  and  the  other  outwards  and  downwards. 
It  has  many  short  excretory  ducts,  which  open  by 
orifices  arranged  in  a line  on  each  side  : they  are 
discovered  with  difficulty  on  account  of  their  small 
size,  and  sometimes  amount  to  eighteen  or  twenty  in 
number.  In  some  few  instances,  this  gland  sends  off 
a single  duct,  which  communicates  with  the  duct  of 
the  submaxillary  gland. 

The  salivary  fluid  secreted  by  these  glands  is  in- 
odorous, insipid,  and  limpid,  like  water ; but  much 
more  viscid,  and  of  greater  specific  gravity.  Water 
constitutes  at  least  four-fifths  of  its  bulk  ; and  animal 
mucus  one-half  of  its  solid  contents.  It  also  contains 
some  albumen,  and  several  saline  substances  : as  the 
muriate  of  soda,  and  the  phosphates  of  lime,  of  soda, 
and  of  ammonia. 

It  is  probable  that  this  fluid  possesses  a solvent 
power  with  respect  to  the  articles  of  food. 

There  are  small  glandular  bodies,  situated  be- 
tween the  masseter  and  buccinator  muscles,  opposite 
to  the  last  molar  tooth  of  the  upper  jaw,  whose  na- 
ture is  not  well  understood  : they  are  called  Gland - 
idee  Molares. 

The  motions  of  the  tongue  are  very,  intelligible  to  a 
person  who  has  a preparation  of  the  lower  jaw  be- 
fore him,  with  the  tongue  in  its  natural  situation,  and 
the  muscles  which  influence  it,  properly  dissected. 
Its  complicated  movements  will  appear  the  neces- 
sary result  of  the  action  of  those  muscles  upon  it, 
and  the  os  hyoides  ; and  also  upon  the  larynx,  with 


28 


Observations  on  the  Tongue. 

which  the  os  hyoides  is  connected.  The  muscular 
fibres  of  the  tongue  itself  are  also  to  be  taken  into 
this  view,  as  they  act  a very  important  part. 
Although  tiie  tongue  appears  very  necessary  in  a me- 
chanical point  of  view,  to  the  articulation  of  many 
words,  yet  there  are  cases  where  it  has  been  entire- 
ly deficient,  in  which  the  parties  thus  aft'ected,  have 
been  able  to  speak  very  well  in  general,  as  well  as 
to  distinguish  different  tastes.* 

The  tongue  is  also  a very  delicate  organ  of  touch — 
We  can  perceive  the  form  of  the  teeth,  and  the  state 
of  the  surface  of  the  mouth,  more  accurately  by  the 
application  of  the  tongue  than  of  the  fingers. 

On  the  three  nerves  which  go  to  the  tongue,  it  is  ge- 
nerally supposed  that  the  Ungual  portion  of  the  third 
branch  of  the  fifth  pair  is  most  immediately  con- 
cerned in  the  function  of  tasting,  as  it  passes  to  the 
front  part  of  the  surface  of  the  tongue.  The  glos- 
so-phuryngeal  are  probably  concerned  in  the  same 
function  on  the  posterior  part,  while  the  ninth  pair 
of  nerves  seems  principally  spent  upon  the  muscu- 
lar parts  of  the  organ. 

It  is  obvious  that  the  tongue  is  most  copiously  supplied 
with  nerves.  This  probably  accounts  for  the  great 
facility  of  its  motions,  and  the  power  of  continu- 
ing them. 

* There  is  a very  interesting  paper  on  this  subject,  in  the  Memoirs  of 
the  Academy  of  Sciences  for  the  year  1718,  by  Jussieu;  in  which  he  de- 
scribes the  case  of  a female,  fifteen  years  old,  examined  by  himself,  who 
was  bom  without  a tongue  . In  this  paper  he  refers  to  another  case,  de- 
scribed by  Rolland,  a surgeon  of  Saumur,  of  a boy  nine  years  old,  whose 
tongue  was  destroyed  by  gangrene.  In  each  of  these  cases  the  subject  was 
able  to  articulate  very  well,  with  the  exception  of  a few  letters;  and  also 
enjoyed  the  sense  of  taste. 


CHAPTER  III. 


OF  THE  THROAT. 

To  avoid  circumlocution,  the  word  throat  is  used 
as  a general  term  to  comprehend  the  structure  which 
occurs  behind  the  nose  and  mouth,  and  above  the 
(Esophagus  and  trachea.  This  structure  consists, 

1st.  Of  the  parts  immediately  behind  the- mouth, 
which  constitute  the  Isthmus  of  the  Fauces  : 

2nd.  Of  the  parts  which  form  the  orifice  of  the 
windpipe,  or  the  Larynx  ; — and 

3d.  Of  the  muscular  bag,  which  forms  the  cavity 
behind  the  nose  and  mouth  that  terminates  in  the 
(Esophagus,  or  the  Pharynx, 

SECTION  I, 

Of  the  Isthmus  of  the  Fauces. 

In  the  back  part  of  the  mouth,  on  each  side,  are  to 
be  seen  the  two  ridges  or  half  arches,  passing  from 
the  soft  palate  of  the  root  of  the  tongue,  mentioned 
in  page  17,  and  said  to  be  formed  by  plaits  of  the 
skin  containing  muscular  fibres.  The  anterior  plait, 
which  contains  the  muscle  called  Constrictor  Isthmi 
Faucium , passes  directly  from  the  side  of  the  root  of 
the  tongue  to  the  palate,  and  terminates  near  the 
commencement  of  the  uvula.  The  posterior  plait 
runs  from  the  palate  obliquely  downwards  and  back- 
wards, as  it  contains  the  palato-pharyngeus  muscle, 
which  passes  from  the  palate  to  the  upper  and  poste- 
rior part  of  the  thyroid  cartilage. 

In  the  triangular  space  between  these  ridges  is 
situated  a glandular  body,  called  the  Tonsil  Jimyg- 


30 


Tonsils — Epiglottis. 

dala.  This  gland  has  an  oval  form,  its  longest  dia- 
meter extending  from  above  downwards.  Its  surface 
is  rather  convex,  its  natural  colour  is  a pale  red.  On 
its  surface  are  the  large  orifices  of  many  cells  of  con- 
siderable size,  which  exist  throughout  the  gland. 
These  cells  often  communicate  with  each  other,  so 
that  a probe  can  be  passed  in  at  one  orifice  and  out 
at  the  other. 

Into  these  cells  open  many  mucous  ducts,  which 
discharge  the  mucus  of  the  throat,  for  the  purpose 
of  lubricating  the  surface,  and  facilitating  the  trans- 
mission of  food. 

Tiie  epiglottis,  or  fifth  cartilage  of  the  larynx,  is 
situated  at  the  root  of  the  tongue,  in  the  middle, 
between  the  tonsils.  The  part  which  is  in  sight  is 
partly  oval  in  form,  and  of  a whitish  colour.  Its 
position,  as  respects  the  tongue,  is  nearly  perpendi- 
cular, and  its  anterior  surface  rather  convex. 

The  membrane  continued  from  the  tongue  over 
the  epiglottis  is  sn  arranged  that  it  forms  a plait, 
which  extends  from  the  middle  of  the  root  of  the 
tongue  along  the  middle  of  the  anterior  surface  of 
the  epiglottis,  from  its  base  upwards. 

On  each  side  of  this  plait,  or  frzenum,  at  the  junc- 
tion of  the  surfaces  of  the  tongue  and  of  the  epiglot- 
tis, there  is  often  a depression,  in  which  small  por- 
tions of  food  sometimes  remain;  and  a small  frsenum, 
similar  to  that  above  described,  is  sometimes  seen  on 
the  outside  of  each  of  these  cavities. 

The  epiglottis  is  situated  immediately  before  the 
opening  into  the  larynx. 

The  above  described  parts  can  be  well  ascertained 
in  the  living  subject,  by  a person  who  has  a general 
knowledge  of  the  structure.  Thus,  looking  into  the 
mouth,  with  the  tongue  depressed,  the  uvula  and  soft 
palate  are  in  full  view  above,  and  the  epiglottis  is 
very  perceptible  below  ; while  the  two  ridges  or  la- 


Of  the  Larynx.  31 

tera]  half  arches  can  be  seen  on  each  side,  with  the 
tonsil  between  them. 

SECTION  II. 

Of  the  Larynx . 

In  this  structure  are  five  cartilages,  upon  which 
its  form  and  stength  depends,  viz.  the  Cricoid , the 
Thyroid,  the  two  Arytenoid , and  the  Epiglottis. 
These  cartilages  are  articulated  to  each  other,  and 
are  supplied  with  muscles  by  which  certain  limited 
motions  are  effected. 

The  basis  of  the  structure  is  a cartilaginous  ring, 
called  the  cricoid  cartilage,  which  may  be  considered 
as  the  commencement  of  the  windpipe. 

It  may  be  described  as  an  irregular  section  of  a 
tube  : its  lower  edge,  connected  with  the  windpipe, 
being  nearly  horizontal  when  the  body  is  erect ; and 
the  upper  edge  very  oblique,  sloping  from  before, 
backwards  and  upwards  : in  consequence  of  this,  it 
has  but  little  depth  before,  but  is  eight  or  nine  lines 
deep  behind. 

The  Thyroid  cartilage  is  a single  plate,  bent  in  such 
manner  that  it  forms  an  acute  angle  with  two  similar 
broad  surfaces  on  each  side  of  it.  It  is  so  applied  to 
the  cricoid  cartilage,  that  the  lower  edge  of  the  angu- 
lar part  is  at  a small  distance  above  the  front  part  of 
that  cartilage,  and  connected  to  it  by  ligamentous 
membrane : while  its  broad  sides  are  applied  to  it 
laterally,  and  thus  partially  enclose  it. 

The  upper  edge  of  the  angular  part  of  the  thyroid 
cartilage  forms  a notch  ; and  the  natural  position  of 
the  cartilage  is  such,  that  this  part  is  very  prominent 
in  the  neck  : it  is  called  the  Pomum  JLdami . 

Both  the  upper  and  lower  edges  of  the  thyroid 
cartilage  terminate  posteriorly  in  processes,  which 


32  Arytenoid  Cartilages  and  Ligaments . 

are  called  Cornua.  The  two  uppermost  are  longest : 
they  are  joined  by  ligaments  to  the  extremities  of  the 
os  hyoid es.  The  lower  and  shorter  processes  are 
fixed  to  the  cricoid  cartilage.  The  thyroid  cartilage, 
therefore,  partly  rests  upon  the  cricoid  cartilage  be- 
low, and  is  attached  to  the  os  hyoides  above.  It  is 
influenced  by  the  muscles  which  act  upon  the  os 
hyoides,  and  also  by  some  muscles  which  are  insert- 
ed into  itself.  It  is  moved  obliquely  downwards  and 
forwards,  in  a slight  degree,  upon  the  cricoid  cartil- 
age by  a small  muscle,  the  crico-thyroideus,  which 
arises  from  that  cartilage  and  is  inserted  into  it. 

The  Arytenoid  cartilages  are  two  small  bodies  of  a 
triangular  pyramidal  form,  but  slightly  curved  back- 
wards. They  are  placed  upon  the  upper  and  poste- 
rior edge  of  the  cricoid  cartilage,  near  to  each  other; 
and  their  upper  ends,  taken  together,  resemble  the 
mouth  of  a pitcher  or  ewer;  from  which  circum- 
stance their  name  is  derived.  Their  bases  are  broad ; 
and  on  their  lower  surfaces  is  a cavity,  which  cor- 
responds with  the  convex  edge  of  the  cricoid  cartil- 
age, to  which  they  are  applied.  At  these  places,  a 
regular  moveable  articulation  is  formed,  by  a capsu- 
lar ligament  between  each  of  these  cartilages  and  the 
cricoid,  in  consequence  of  which  they  can  be  incli- 
ned backward  or  forward,  inward  or  outward. 

From  the  anterior  part  of  each  of  these  cartilages, 
near  the  base,  a tendinous  cord  passes  forward,  in  a 
direction  which  is  horizontal  when  the  body  is  erect, 
to  the  internal  surface  of  the  angle  of  the  thyroid. 
These  ligaments  are  not  perfectly  parallel  to  each 
other ; for  they  are  nearer  before  than  behind.  The 
aperture  between  them  is  from  two  to  five  lines  wide 
when  the  muscles  are  not  in  action  ; and  this  aperture 
is  the  orifice  of  the  windpipe  : for  the  exterior  space, 
between  these  ligaments  and  the  circumference  of 
the  thyroid,  is  closed  up  by  membrane  and  muscle. 


33 


Epiglottis. 

At  a small  distance  above  these  ligaments  are  two 
others,  which  also  pass  from  the  arytenoid  to  the 
thyroid  cartilages.  They  are  not  so  tendinous  and 
distinct  as  the  first  mentioned,  and  cannot  be  drawn 
so  tense  by  the  muscles  of  the  arytenoid  cartilages. 
They  are  also  situated  at  a greater  distance  from  each 
other,  and  thus  form  a large  aperture. 

On  the  external  side  of  the  upper  extremity  of 
each  of  the  arytenoid  cartilages,  and  nearly  in  con- 
tact with  it,  is  a small  cartilaginous  body,  not  so  large 
as  a grain  of  wheat,  and  nearly  oval  in  form.  These 
are  connected  firmly  to  the  arytenoid  cartilages,  and 
are  called  their  appendices.  Being  in  the  margin  of 
the  aperture  of  the  larynx,  they  have  an  effect  upon 
its  form. 

The  arytenoid  cartilages  are  the  posterior  parts 
of  the  larynx : the  Epiglottis , which  has  already 
been  mentioned,  is  the  anterior.  When  this  carti- 
lage is  divested  of  its  membrane,  it  is  oval  in  its 
upper  extremity,  and  rather  angular  below,  termi- 
nating in  a long  narrow  process,  which  is  like  the 
stalk  of  a leaf.  It  is  firmly  attached  to  the  internal 
surface  of  the  angular  part  of  the  thyroid  by  this 
lower  process ; and,  being  placed  in  a perpendicular 
position,  one  of  its  broad  surfaces  is  anterior  towards 
the  tongue,  and  the  other  posterior,  towards  the  open- 
ing of  the  windpipe. 

It  is  attached  to  the  os  hyoides  by  dense  cellular 
texture  or  ligament,  and  to  the  tongue  by  those  plaits 
of  the  membrane  of  the  mouth,  which  have  been  al- 
ready described. 

It  is  elastic,  but  more  flexible  than  the  oth*f  car- 
tilages ; being  somewhat  different  in  its  structure.— 
Its  surface  is  perforated  by  the  orifices  of  many  mu- 
cus ducts. 

There  is  a small  .space  between  the  lower  part  of 
this  cartilage,  and  the  upper  part  of  the  thyroid  and 
Vol.  ii„  5 


34 


liima  Glottidis. — Glottis. 


the  ligamentous  membrane  passing  from  it  to  the  os 
hyoides.  In  this  is  a substance,  which  appears  to 
consist  of  glandular  and  of  adipose  matter.  It  is  sup- 
posed that  some  of  the  orifices  on  the  lower  part  of 
the  epiglottis  communicate  with  this  substance. 

In  the  erect  position  of  the  body,  the  epiglottis  is 
situated  rather  higher  up  than  the  arytenoid  carti- 
lages, and  at  the  distance  of  ten  or  twelve  lines  from 
them. 

The  membrane  which  covers  the  epiglottis,  is  ex- 
tended from  each  side  of  it  to  the  arytenoid  carti- 
lages ; and  being  continued  into  the  cavity  of  the  la- 
rynx, as  well  as  upon  the  general  surface  of  the 
throat,  it  is  necessarily  doubled  : this  doubling  forms 
the  lateral  margins  of  the  orifice  of  the  cavity  of  the 
larynx.  In  these  folds  of  the  membrane  are  seen 
very  delicate  muscular  fibres,  called  the  Aryteno- 
epiglottidei. 

The  membrane  continues  down  the  cavity  of  the 
larynx,  and,  covering  the  upper  ligaments,  pene- 
trates into  the  vacuity  between  them  and  the  lower 
ligaments,  so  as  to  form  a cavity  on  each  side  of  the 
larynx,  opening  between  the  two  ligaments,  which 
is  called  the  Ventricle  of  Morgagni.  The  shape  of 
these  cavities  is  oblong.  Its  greatest  length  extends 
from  behind  forward,  on  each  side  of  the  opening 
into  the  windpipe  formed  by  the  two  lower  or  prin- 
cipal ligaments;  so  that  when  the  larynx  is  removed 
from  the  subject,  upon  looking  into  it  from  above, 
ytri  perceive  three  apertures : one  in  the  middle, 
formed  by  the  two  lower  ligaments ; and  one  on 
each  ode  of  it,  between  the  lower  and  upper  liga- 
ment, Vvfiich  is  the  orifice  of  the  ventricle  of  Mor- 
gagni. 

The  apertore  between  the  two  lower  ligaments  is 
called  the  Uinta,  Gloitidis,  or  Chink  of  the  Glottis  $ 
the  upper  aperture,  formed  by  the  fold  of  the  mem- 


35 


Arteries  and  jXerves  of  the  Larynx . 

brane  extending  from  the  epiglottis  to  the  arytenoid 
cartilages,  may  be  termed  Glottis. 

If  the  windpipe  is  divided  near  the  larynx,  and 
the  larynx  inverted,  so  that  the  rima  glottidis,  may 
be  examined  from  below,  the  structure  appears  still 
more  simple  : it  resembles  a septum  fixed  abruptly 
in  the  windpipe,  with  an  aperture  in  it  of  the  figure 
of  the  rima  glottidis.  . 

The  anterior  surface  of  the  two  arytenoid  cartila- 
ges is  concave.  This  concavity  is  occupied  in  each 
by  a glandular  substance,  which  lies  between  the  car- 
tilage and  the  lining  membrane  ; and  extends  itself 
horizontally,  covered  by  the  upper  ligament  of  the 
glottis.  The  nature  of  these  bodies  is  not  perfectly 
understood  j but  they  are  supposed  to  secrete 
mucus. 

The  membrane,  which  lines  the  cavity  of  the  glot- 
tis being  continued  from  the  mouth  and  throat,  re- 
sembles the  membranes  which  invest  those  parts.  In 
some  places,  where  it  is  in  close  contact  with  the  car- 
tilages, it  appears  united  with  the  perichondrium, 
and  acquires  more  firmness  and  density. 

The  general  motions  of  the  larynx  are  very  intel- 
ligible to  those  who  are  acquainted  with  the  muscles 
which  are  connected  with  the  thyroid  cartilage,  and 
which  move  the  os  hyoides  They  take  place  par- 
ticularly in  deglutition,  and  in  some  modifications  of 
the  voice  ; and  also  in  vomiting. 

The  motions  of  the  particular  cartilages  on  each 
other  can  also  be  well  understood,  by  attending  to 
the  origin  and  insertion  of  the  various  small  muscles 
connected  with  them.  The  most  important  of  these 
muscles  are  the  crico-arytenoidei  postici  and  late- 
rales,  the  thyreo-arytenoidei,  the  arytenoidei  obliqui, 
and  the  arytenoideus  transversus.  The  effects  of 
their  actions  appear  to  be  the  dilating  or  contracting 


36 


Arteries  and  JYerves  of  the  Larynx. 

the  rima  glottidis,  and  relaxing  or  extending  the  li- 
gaments which  form  it. 

The  arteries  of  the  larynx  are  derived  from  two 
sources,  viz.  the  superior  thyroid,  or  laryngeal 
branch  of  the  external  carotid  ; and  the  thyroid 
branch  of  the  subclavian. 

The  nerves  of  the  larynx  also  come  to  it  in  two 
very  different  directions  on  each  side.  It  receives 
two  branches  from  the  par  vagum  ; one  which  leaves 
that  nerve  high  up  in  the  neck,  and  is  called  the 
Superior  Laryngeal  branch  ; and  another  which 
proceeds  from  it  after  it  has  passed  into  the  cavity 
of  the  thorax,  and  is  called  from  its  direction  the 
Recurrent. 


The  extreme  irritability  of  the  glottis  is  unequivocally 
demonstrated  by  the  cough  which  is  excited  when  a 
drop  of  water,  or  any  other  mild  liquid,  or  a crumb 
of  bread  enters  it.  Notwithstanding'  this,  a flexi- 
ble tube,  or  catheter,  has  several  times  been  passed 
into  the  windpipe  through  the  rima  glottidis,  and 
been  endured  by  the  patient  a considerable  time. 

The  cough,  which  occurs  when  these  parts  are  irritated, 
does  not  appear  to  arise  exclusively  from  the  irrita- 
tion of  the  membrane  within  the  glottis  ; for,  it  it 
were  so,  mucilaginous  substances,  when  swallowed 
slowly,  could  not  suspend  it.  Their  effect  in  reliev- 
ing cough  is  universally  known  ; and  as  they  are  only 
applied  to  the  surface  exterior  to  the  glottis,  it  is  evi- 
dent that  the  irritation  of  this  surface  must  also  pro- 
duce coughing. 

Several  curious  experiments  have  been  made  to  deter- 
mine the  effect  of  dividing  the  different  nerves  which 
go  to  the  larynx  ; by  which  it  appears  that  the  re- 
current branches  supply  parts  which  are  essentially 
necessary  to  the  formation  of  the  voice,  whilst  the 
laryngeal  branches  supply  parts  which  merely  in- 
fluence its  modulation,  or  tone.  See  Mr.  Haighton’s 
Essay  on  this  subject : Memoirs  of  the  Medical  So- 
ciety of  London,  Vol.  III. 


The  Thyroid  Gland. — The  Pharynx.  37 


The  Thyroid  Gland 

May  be  described  here,  although  a part  of  it  is 
situated  below  the  larynx. 

This  body  consists  of  two  lobes,  which  are  united 
at  their  lower  extremities  by  a portion  which  extends 
across  the  anterior  part  of  the  windpipe.  Each  lobe 
generally  rises  upwards  and  backwards  from  the  se- 
cond cartilaginous  ring  of  the  windpipe  over  the  cri- 
coid cartilage  and  a portion  of  the  thyroid.  It  lies 
behind  the  sterno-hyoidei  and  sterno-tliyroidei  mus- 
cles. It  is  of  a reddish-brown  colour,  and  appears 
to  consist  of  a granulous  substance  ; but  its  ultimate 
structure  is  not  understood.  It  is  plentifully  suppli- 
ed with  blood,  and  receives  two  arteries  on  each  side : 
one  from  the  laryngeal  branch  of  the  external  caro- 
tid : and  the  other  from  the  thyroid  branch  of  the 
subclavian. 

Notwithstanding  this  large  supply  of  blood,  there 
is  no  proof  that  it  performs  any  secretion ; for  al- 
though several  respectable  anatomists  have  supposed 
that  they  discovered  excretory  ducts  passing  to  the 
windpipe,  larynx,  or  tongue,  it  is  now  generally 
agreed  that  such  excretory  ducts  are  not  to  be  found. 
Several  instances  have  however  occurred,  in  which 
air  has  been  forced,  by  violent  straining,  from  the 
windpipe  into  the  substance  of  this  gland.* 

* There  are  two  membranous  expansions  in  the  neck  which  should  be 
noticed  in  its  dissection.  The  first  called  Fascia  Superficialis  lies  imme- 
diately beneath  the  skin,  may  be  considered  as  a continuation  of  the  fascia 
superficialis  abdominis,  and  is  strongly  connected  to  the  base  of  the  lower 
jaw,  being  also  spread  over  the  parotid  gland.  It  is  not  very  distinct  in  all 
subjects.  The  second  is  called  the  Fascia  Profunda  Cervicis;  it  extends 
from  the  larynx  and  thyroid  gland  to  the  upper  part  of  the  sternum  and 
first  ribs,  the  great  vessels,  &c.  of  the  superior  mediastinum  are  placed 
immediately  below  it. — Ed. 


38 


Structure  of  the  Pharynx . 


SECTION  III. 

Of  the  Pharynx. 

The  pharynx  is  a large  muscular  bag.  which  forms 
the  great  cavity  behind  the  nose  and  mouth  that  ter- 
minates in  the  oesophagus. 

It  has  been  compared  to  a funnel,  of  which  the 
oesophagus  is  the  pipe  : but  it  differs  from  a funnel 
in  this  respect,  that  it  is  incomplete  in  front,  at  the 
part  occupied  by  the  nose  and  mouth  and  larynx. 

It  is  connected  above,  to  the  cuneiform  process  of 
the  occipital  bone,  to  the  pterygoid  processes  of  the 
sphenoidal,  and  to  both  the  upper  and  lower  maxil- 
lary bones.  It  is  in  contact  with  the  cervical  verte- 
brae behind  ; and,  opposite  to  the  cricoid  cartilage, 
it  terminates  in  the  oesophagus. 

If  the  pharynx  and  oesophagus  be  carefully  dissect- 
ed and  detached  fi  om  the  vertebrae,  preserving  the 
connexion  of  the  pharnx  with  the  head  ; and  the  head 
then  be  separated  from  the  body,  by  dividing  the 
articulation  of  the  atlas  and  the  os  oceipitis,  and  cut- 
ting through  the  soft  parts  below  the  larynx  ; the 
resemblance  to  a funnel  will  be  very  obvious. 

In  this  situation,  if  an  incision  be  made  from 
above  downwards  though  the  whole  extent  of  the 
posterior  part  of  the  pharynx,  the  communication  of 
the  nose,  mouth,  and  windpipe,  wdth  this  cavity, 
will  be  seen  from  behind  at  one  view. 

The  openings  into  the  nose,  or  the  posterior  nares, 
appear  uppermost.  Their  figure  is  irregularly  oval 
or  oblong  ; they  are  separated  from  each  other  by  a 
thin  partition,  the  vomer.  Immediately  behind,  on 
the  external  side  of  each  of  these  orifices,  is  the 
Eustachian  tube. 

The  soft  palate  will  appear  extending  from  the 
Jowrer  boundary  of  the  posterior  nares,  obliquely 


Structure  of  the  Pharynx . 39 

backwards  and  downwards,  so  as  nearly  to  close  the 
passage  into  the  mouth.  The  uvula  hangs  from  it ; 
and,  on  each  side  of  the  uvula,  the  edge  of  the  palate 
is  regularly  concave. 

Below  the  palate,  in  the  isthmus  of  the  fauces,  are 
the  ridges  or  half-arches,  and  the  tonsils  between 
them.  The  half-arch  which  presents  first,  in  this 
view,  runs  obliquely  downward  and  backward,  and 
not  parallel  to  the  other. 

Close  to  the  root  of  the  tongue  is  the  epiglottis 
erect ; and,  immediately  adjoining  it,  is  an  aperture 
large  enough  to  admit  the  end  of  a middle-sized 
finger.  This  aperture  is  widest  at  the  extremity 
next  to  the  epiglottis,  and  rather  narrower  at  the 
other  extremity  : it  is  the  glottis  or  opening  of  the 
windpipe.  When  the  larynx  is  elevated,  the  epi- 
glottis can  be  readily  depressed  so  as  to  cover  it 
completely. 

The  extremities  of  the  arytenoid  cartilages,  and 
their  appendices,  may  be  recognised  at  the  posterior 
edge  of  the  glottis.  At  a short  distance  below  this 
edge,  the  (Esophagus  begins. 

The  Pharynx  is  composed  of  the  membrane  con- 
tinued from  the  nose  and  mouth  internally,  and  of  a 
stratum  of  muscular  fibres  externally.  The  internal 
membrane  is  very  soft  and  flexible,  and  perforated 
by  many  muciferous  ducts.  The  surface  which  it 
forms  is  rather  rough,  owing  to  the  mucous  glands 
which  it  covers.  It  has  a red  colour,  but  not  so  deep 
as  that  of  some  other  parts.  It  is  connected  to  the 
muscular  stratum  by  a loose  cellular  membrane. 

The  muscular  coat  consists  of  three  different  por- 
tions, which  are  considered  as  so  many  distinct  mus- 
cles. 

The  fibres  of  each  of  these  muscles  originate  on 
each  side,  and  run  in  an  oblique  direction  to  meet  in 


40  Structure  of  the  Pharynx. 

the  middle,  thus  forming  the  posterior  external  sur- 
face of  the  dissected  pharynx. 

The  fibres  of  the  upper  muscle  originate  from  the 
cuneiform  process  of  the  occipital  bone,  from  the 
pterygoid  processes  of  the  os  sphenoides,  and  from 
the  upper  and  lower  jaws,  near  the  last  dentes  mo- 
lares,  on  each  side.  They  unite  in  a middle  line  in 
the  back  of  the  pharynx. 

The  fibres  of  the  middle  muscle  originate  princi- 
pally from  the  lateral  parts  of  the  os  hyoides,  and. 
from  the  ligaments  which  connect  that  bone  to  the 
thyroid  cartilage.  The  superior  fibres  run  obliquely 
upwards,  so  as  to  cover  a part  of  the  first  mentioned 
muscle,  and  terminate  in  the  cuneiform  process  of  the 
occipital  bone;  while  the  other  fibres  unite  with 
those  of  the  opposite  side  in  the  middle  line. 

The  fibres  of  the  lower  muscles  arise  from  the  thy- 
roid and  the  cricoid  cartilages,  and  terminate  also  in 
the  middle  line.  Those  which  are  superior,  running 
obliquely  upwards  ; the  inferior,  nearly  in  a trans- 
verse direction. 

It  is  obvious,  from  the  origin  and  insertion  of 
these  fibres,  that  the  pharynx  must  have  the  power 
of  contracting  its  dimensions  in  every  respect ; and, 
particularly,  that  its  diameter  may  be  lessened  at 
any  place  ; and  that  the  whole  may  be  drawn  up- 
wards. 


SYSTEM  OF  ANATOMY. 


PART  VII. 


OF  THE  THORAX. 

Before  the  thorax  is  described,  it  will  be  in  or- 
der to  consider  the 

Mammse  ; 

Or  those  glandular  bodies,  situated  on  the  anterior 
part  of  it,  which,  in  females,  are  destined  to  the  se- 
cretion of  milk. 

These  glands  lie  between  the  skin  and  the  pecto- 
ral muscles,  and  are  attached  to  the  surfaces  of  those 
muscles  by  cellular  membrane. 

They  are  of  a circular  form  ; and  consist  of  a 
whitish  firm  substance,  divisible  into  small  masses  or 
lobes,  which  are  composed  of  smaller  portions  or  lo- 
buli.  Between  these  glandular  portions  a great  deal 
of  adipose  matter  is  so  diffused,  that  it  constitutes  a 
considerable  part  of  the  bulk  of  the  mammse. 

The  gland,  however,  varies  greatly  in  thickness  in 
the  same  person  at  different  periods  of  life. 

The  mammas  become  much  enlarged  about  the 
age  of  puberty.  They  are  also  very  large  during 
pregnancy  and  lactation  ; but  after  the  period  of 
child-bearing,  they  diminish  considerably.  They 
are  supplied  with  blood  by  the  external  and  internal 

VOLv  II.  © 


42 


Mammae. 


maniary  arteries,  the  branches  of  which  enter  them 
irregularly  in  several  different  places. 

The  veins  correspond  with  the  arteries. 

From  the  small  glandular  portions  that  compose 
the  mamma,  fine  excretory  tubes  arise,  which  unite 
together  and  form  the  great  lactiferous  ducts  of  the 
gland.  These  ducts  proceed  in  a radiated  manner 
from  the  circumference  to  the  centre,  and  terminate 
on  the  surface  of  the  nipple.*' 

They  are  commonly  about  fifteen  in  number,  and 
vary  considerably  in  size  : the  largest  of  them  being 
more  than  one-sixth  of  an  inch  in  diameter. 

They  can  be  very  readily  injected  by  the  orifices 
of  the  nipple,  from  a pipe  filled  with  mercury,  in 
subjects  who  have  died  during  lactation  or  pregnan- 
cy; but  they  are  very  small  in  subjects  of  a differ- 
ent description. 

It  has  been  asserted  by  respectable  anatomists,  that 
these  ducts  communicate  freely  with  each  other  ; but 
they  do  not  appear  to  do  so  : each  duct  seems  to  be 
connected  with  its  proper  branches  only.f 

Haller  appears  to  have  entertained  the  remarkable 
sentiment , that  some  of  the  ducts  originated  in  the 
adipose  matter  about  the  gland,  as  well  as  in  the  glan- 
dular substance.;}: 

The  papilla,  or  nipple,  in  which  these  ducts  ter- 
minate, is  in  the  centre  of  the  mamma  : it  consists  of 
a firm  elastic  substance,  and  is  nearly  cylindrical  in 
form.  It  is  rendered  tumid  by  irritation,  and  by 
certain  emotions. 

The  lactiferous  ducts  terminate  upon  its  extremi- 
ty. When  it  is  elongated  they  can  freely  discharge 

* Described  in  the  16th  century,  by  Charles  Etienne,  Vesalius  and  Pos- 
thuis,  but  their  uses  were  unknown. — Ed. 

t See  Edinburgh  Medical  Commentaries,  vol.  1.  page  31 — a paper  by 
Meckel.  Ed. 

t Elemeuta  Physiologise,  Tom.  7,  Pars  11,  page  7. 


Mammas.  43 

their  contents ; but  when  it  contracts,  this  discharge 
is  impeded. 

The  skin  immediately  around  the  nipple  is  of  a 
bright  red  colour  in  virgins  of  mature  age.  In  preg- 
nant women  it  is  sometimes  almost  black  ; and  in 
women  who  have  borne  children  it  is  often  brownish. 
It  abounds  with  sebaceous  glands,  which  form  small 
eminences  on  its  surface. 

This  gland  exists  in  males,  although  it  is  very 
small.  In  boys,  soon  after  birth,  it  has  often  been 
known  to  tumefy  and  become  very  painful,  in  conse- 
quence of  the  secretion  and  accumulation  of  a whitish 
fluid,  which  can  be  discharged  by  pressure.  It  also 
sometimes  swells  and  is  painful,  in  males  at  the  age 
of  puberty. 

There  have  been  some  instances  in  which  it  has 
secreted  milk  in  adult  males  ; and  a few  instances 
also  in  which  it  has  been  affected  with  cancer,  in  the 
same  sex. 

The  mamma  is  plentifully  supplied  with  absorbent 
vessels,  which  pass  from  it  to  the  lymphatic  glands 
in  the  axilla. 

Its  nerves  are  principally  derived  from  the  great 
plexus  formed  by  the  nerves  of  the  arm. 


CHAPTER  I. 


OF  THE  GENERAL  CAVITY  OF  THE  THORAX. 

SECTION  I. 

Of  the  form  of  the  Cavity  of  the  Thorax. 

The  osseous  structure  of  the  thorax  is  described 
in  vol.  i.  page  94.  The  cavity  is  completed  by  the 
intercostal  muscles,  which  dose  the  vacuities  between 
the  ribs;  and  by  the  diaphragm,  which  fills  up  the 
whole  space  included  within  its  lower  margin. 

If  we  except  the  apertures  of  the  diaphragm, 
which  are  completely  occupied  by  the  aor  ta,  the  vena 
cava,  and  the  oesophagus,  &c.  the  only  outlet  of  this 
cavity  is  above  : it  is  formed  by  the  upper  ribs,  the 
first  dorsal  vertebra,  and  the  sternum.  The  figure 
of  this  aperture  is  between  that  of  the  circle  and  the 
oval  ; but  it  is  made  irregular  by  the  vertebra,  and 
by  the  upper  edge  of  the  sternum. 

When  the  superior  extremities  and  the  muscles 
appropriated  to  them  are  removed,  the  external  figure 
of  the  thorax  is  conical  ; but  the  cavity  formed  hy  it 
is  considerably  influenced  by  the  spine,  which  pro- 
trudes into  it ; while  the  ribs,  as  they  proceed  from 
the  spine,  curve  backwards,  and  thus  increase  its 
prominency  in  the  cavity. 

The  diaphragm  has  a great  effect  upon  the  figure 
of  the  cavity  of  the' thorax.  It  protrudes  into  it  from 
below  , with  a convexity  of  such  form  that  it  has  been 
compared  to  an  inverted  bowl  ; so  that,  although  it 
arises  from  the  lower  margin  of  the  thorax,  the  cen- 
tral parts  of  it  are  nearly  as  high  as  the  fourth  rib. 


Pleurse. 


45 


The  position  of  the  diaphragm  is  also  oblique. 
The  anterior  portion  of  its  margin,  being  connected 
to  the  seventh  and  eighth  ribs,  is  much  higher  than 
the  posterior  portion,  which  is  attached  to  the  eleventh 
and  twelfth. 

In  consequence  of  the  figure  and  position  of  the 
diaphragm,  the  form  of  the  cavity  of  the  thorax  re- 
sembles that  of  the  hoof  of  the  ox  when  its  posterior 
part  is  presented  forwards. 

SECTION  II. 

Of  the  arrangement  of  the  Plearse. 

The  thorax  contains  the  two  lungs  and  heart,  as 
well  as  several  very  important  parts  of  smaller  size. 

The  lungs  occupy  the  greatest  part  of  the  cavity; 
and  to  each  of  them  is  appropriated  a complete  sac, 
called  Pleura , which  is  so  arranged  that  it  covers 
the  surface  of  the  lungs,  and  is  continued  from  it  to 
the  contiguous  surface  of  the  thorax,  which  it  hues. 
After  covering  the  lung,  it  is  extended  from  it  to  the 
spine  posteriorly,  and  the  sternum  anteriorly : so 
that  in  tracing  the  pleura  in  a circular  direction,  if 
you  begin  at  the  sternum,  it  proceeds  on  the  inside 
of  the  ribs  to  the  spine  ; at  the  spine  it  leaves  the 
surface  of  the  thorax,  and  proceeds  directly  forwards 
towards  the  sternum.  In  its  course  from  the  spine 
to  the  sternum,  it  soon  meets  with  the  great  branch 
of  the  windpipe  and  the  blood  vessels,  which  go  to 
the  lung  : it  continues  on  these  vessels  and  round  the 
lung  until  it  arrives  at  the  anterior  side  of  the  ves- 
sels, when  it  again  proceeds  forwards  untii  it  arrives 
at  the  sternum.  Each  sac  being  arranged  in  the 
same  way,  there  is  a part  of  each  extended  from  the 
spine  to  the  sternum.  These  two  lamina,  form  the 
great  vertical  septum  of  the  thorax,  called  Mediasti- 
num. They  are  situated  at  some  distance  from  each 


46 


Mediastinum. 


other ; and  the  heart,  with  its  investing  membrane  or 
pericardium,  is  placed  between  them. 

The  pericardium  is  also  a complete  sac  or  blad- 
der, which,  after  covering  perfectly  the  surface  of 
the  heart,  is  extended  from  it  so  as  to  form  a sac, 
which  lies  loose  about  it,  and  appears  to  contain  it. 
This  loose  portion  adheres  to  those  parts  of  the  la- 
mina of  the  mediastinum  with  which  it  is  contigu- 
ous ; and  thus  three  chambers  are  formed  within  the 
cavity  of  the  thorax : one  for  each  lung,  and  one  for 
the  heart. 

The  two  lamina  of  the  pleura,  which  constitute 
the  mediastinum,  are  at  different  distances  from  each 
other,  in  different  places.  At  the  upper  part  of  the 
thorax,  they  approach  each  other  from  the  internal 
edges  of  the  first  l ibs ; and,  as  these  include  a space 
which  is  nearly  circular,  the  vacuity  between  these 
lamina  is  necessarily  of  that  form,  at  its  commence- 
ment above. 

Here,  therefore,  is  a space  between  them  above, 
which  is  occupied  by  the  great  transverse  vein  that 
carries  the  blood  of  the  left  subclavian  and  the  left 
internal  jugular  to  the  superior  cava  ; by  the  trachea; 
by  the  oesophagus ; and  by  the  subclavian  and  caro- 
tid arteries,  as  they  rise  from  the  curve  of  the  aorta. 
This  space  is  bounded  below  by  the  above  mentioned 
curve  of  the  aorta. 

The  heart  and  pericardium  are  so  placed  that 
there  is  a small  distance  between  them  and  the  ster- 
num : in  this  space  the  two  lamina  of  the  mediasti- 
num are  very  near  to  each  other ; and  cellular  sub- 
stance intervenes  between  them.  This  portion  of  the 
mediastinum  is  called  the  Anterior  Mediastinum. 

Posteriorly,  the  heart  and  pericardium  are  also  at 
a small  distance  from  the  spine ; and  here  the  lami- 
na of  the  mediastinum  are  at  a greater  distance  from 
each  other,  and  form  a long  narrow  cavity  which 


47 


Preparation  of  the  Thorax. 

extends  down  the  thorax  in  front  of  the  vertebrae : 
this  is  called  the  Posterior  Mediastinum.  It  con- 
tains a considerable  portion  of  the  aorta  as  it  de- 
scends from  its  curve,  the  oesophagus,  the  thoracic 
duct,  and  the  vena  azygos.  The  aorta  is  in  contact 
with  the  left  lamen,  and  can  often  be  seen  through 
it  when  the  left  lung  is  lifted  up. 

The  oesophagus,  is  in  contact  with  the  right  la- 
men  : in  its  progress  downwards,  it  inclines  to  the 
left  side  and  is  advanced  before  the  aorta. 

The  vena  azygos  appears  posterior  to  the  oesopha- 
gus ; it  proceeds  upwards  until  it  is  as  high  as  the 
right  branch  of  the  windpipe  : here  it  bends  forward, 
round  that  branch,  and  opens  into  the  superior  cava, 
before  that  vein  opens  into  the  right  auricle. 

The  thoracic  duct  proceeds  upwards  from  below, 
lying  in  the  space  between  the  aorta  and  the  vena 
azygos,  until  the  beginning  of  the  curve  of  the  aorta, 
when  it  inclines  to  the  left,  proceeding  towards  the 
place  of  its  termination. 

The  formation  of  the  mediastinum,  and  the  arrangement 
of  the  pleura,  as  well  as  the  connexion  of  these  mem- 
branes with  the  parts  contained  in  the  thorax,  may  be 
studied  advantageously,  after  the  subject  has  been  pre- 
pared in  the  manner  now  to  be  described. 

Take  away,  from  each  side,  the  five  ribs  which  are  situ- 
ated between  the  first  and  last  true  ribs,  by  separating 
their  cartilages  from  the  sternum,  and  their  heads  from 
the  spine  ; so  that  the  great  cavities  of  the  thorax  may 
be  laid  open. 

The  precise  course  of  the  mediastinum  is  thus  rendered 
obvious ; and  the  sternum  may  now  be  divided  with  a 
saw  throughout  its  whole  length  in  the  same  direction  ; 
so  that  the  division  of  the  bone  may  correspond  with 
the  space  between  the  lamina  of  the  mediastinum. 

Separate  the  portion  of  the  sternum  cautiously,  so  as  to 
avoid  lacerating  the  lamina  of  mediastinum;  and  keep 
them  separate,  while  the  trachea  is  dissected  from  the 
neck  into  the  cavity  of  the  thorax ; the  great  transverse 
vein  and  the  descending  cava  are  dissected  to  the  pe= 


48 


Preparation  of  the  Thorax . 

ricardium  ; and  tire  left  carotid  artery,  with  the  right 
subclavian  and  carotid,  are  dissected  to  the  curve  of 
the  aorta,  taking  care  not  to  destroy  the  lamina  of  the 
mediastinum. 

After  this  preparation  the  upper  space  between  the  la- 
mina of  the  mediastinum  can  be  examined  ; and  the 
relative  situation  of  the  trachea  and  the  great  vessels 
in  it  can  be  understood.  The  anterior  mediastinum 
can  also  be  studied  : the  root  of  each  lung,  or  its  con- 
nexion with  the  mediastinum,  may  be  seen  perfectly  ; 
and  the  precise  situation  of  the  lung,  in  its  proper  ca- 
vity, may  be  well  conceived. 

After  this,  while  the  portions  of  the  sternum  are  separa- 
ted, the  pericardium  may  be  opened,  and  the  heart 
brought  into  view:  the  attachment  of  the  pericardium, 
and  to  the  mediastinum,  and  to  the  diaphragm,  may 
be  seen  with  advantage  in  this  situation.  The  por- 
tions of  the  sternum  may  now  be  detached  from  the 
ribs,  with  which  they  remain  connected  ; and  further 
dissection  may  be  performed  to  examine  the  posterior 
mediastinum  and  its  contents,  and  the  parts  which 
constitute  the  roots  of  the  lungs. 


CHAPTER  II. 


OF  THE  HEART  AND  THE  PERTCARDIUM,  AND  THE 

GREAT  VESSELS  CONNECTED  WITH  THE  HEART. 

SECTION  I. 

Of  the  Pericardium . 

The  heart  is  enclosed  by  a membranous  sac, 
which,  upon  a superficial  view,  seems  only  con- 
nected with  its  great  vessels : but  which,  in  fact, 
adheres  closely  to  the  whole  of  its  surface.  From 
this  surface  it  is  extended  to  those  vessels ; from 
which  it  proceeds,  after  the  manner  of  the  reflected 
membranes,  and  forms  an  enclosure  that  lies  loosely 
about  the  heart.  If  it  were  dissected  from  the  heart, 
without  laceration  or  wounding,  it  would  be  an  en- 
tire sac. 

The  pericardium,  thus  arranged,  is  placed  between 
the  two  lamina  of  the  mediastinum,  and  adheres  firm- 
ly to  them  where  they  are  contiguous  to  it : it  also 
adheres  firmly  to  the  diaphragm  below,  and  thus  pre- 
serves the  heart  in  its  proper  position. 

The  figure  of  the  pericardium,  when  it  is  distend- 
ed, is  somewhat  conical;  the  base  being  on  the  dia- 
phragm. The  cavity  formed  by  it  is  larger  than  the 
heart  after  death,  but  it  is  probable  that  the  heart 
nearly  fills  it  during  life  ; for,  when  this  organ  is  dis- 
tended by  injection,  it  often  occupies  the  whole  ca- 
vity of  the  pericardium. 

The  pericardium  is  composed  of  two  lamina,  the 
internal  of  which  covers  the  heart,  as  has  been  al- 
ready described  : while  the  external  merely  extend^ 
over  the  loose  portion  of  the  other,  and  blends 

Vol.  ii.  7 


50  Of  the  Heart. 

with  the  mediastinum,  where  that  membrane  invests 
the  great  vessels. 

The  interna]  surface  of  the  pericardium  is  very 
smooth  and  polished  ; and  in  the  living  subject  is 
constantly  moistened*  with  a fluid,  which  is  probably 
effused  from  the  exhalent  vessels  on  its  surface. 

The  quantity  of  this  fluid  does  not  commonly  ex- 
ceed two  drachms  ; but  in  cases  of  disease  it  some- 
times amounts  to  many  ounces.*  It  is  naturally  trans- 
parent, but  slightly  tinged  with  red  in  children,  and 
yellow  in  old  persons.  It  is  often  slightly  tinged 
with  red  in  persons  who  have  died  by  violence. 

SECTION  II. 

Of  the  Heart. 

The  great  organ  of  the  circulation  consists  of  mus- 
cular fibres,  which  are  so  arranged  that  they  give  it 
a conical  form,  and  compose  four  distinct  cavities 
within  it. 

Two  of  these  cavities,  which  are  called  Auricles, 
receive  the  contents  of  the  veins ; the  other  two  com- 
municate with  the  arteries,  and  are  called  Ventricles. 

The  auricles  form  the  basis  of  the  cone ; the  ven- 
tricles the  body  and  apex. 

The  structure  of  the  auricles  is  much  less  firm 
than  that  of  the  ventricles,  and  consists  of  a smaller 
proportion  of  muscular  fibres.  They  appear  like  ap- 
pendages of  the  heart,  while  the  ventricles  compose 
the  body  of  the  viscus. 

The  ventricles  are  very  thick,  and  are  composed 
of  muscular  fibres  closely  compacted. 

* The  pericardium  has  been  so  distended,  by  effusion  in  dropsy,  that  it 
'•*as  forrne  ) a tumour,,  protruding  on  the  neck  from  under  the  sternum.  This 
tumour  haci  a strong  pulsating  motion.  It  disappeared  completely  when 
the  o^f  hydropic  symptoms  were  relieved. 


51 


Connexions  of  the  Heart, 

The  figure  of  the  heart  is  not  regularly  conical : for 
a portion  of  it,  extending  from  the  apex  to  the  base, 
is  flattened  ; and  in  its  natural  position,  this  flat  part 
of  the  surface  is  downwards. 

It  is  placed  obliquely  in  the  body ; so  that  its  base 
presents  backward  and  to  the  right,  and  its  apex 
forward  and  to  the  left. 

Notwithstanding  this  obliquity,  the  terms  right 
and  left  are  applied  to  the  different  sides  of  the  heart, 
and  to  the  different  auricles  and  ventricles ; although 
they  might,  with  equal  propriety,  be  called  anterior 
and  posterior. 

The  two  great  veins,  called  Venae  Ccwas,  which 
bring  the  blood  from  every  part  of  the  body,  open 
into  the  right  auricle  from  above  and  below  ; the 
right  auricle  opens  into  the  right  ventricle  ; and  from 
this  ventricle  arises  the  artery  denominated  Pulmo- 
nary, which  passes  to  the  lungs. 

The  Pulmonary  veins,  which  bring  back  the  blood 
from  the  lungs,  open  into  the  left  auricle  ; this  auri- 
cle opens  into  the  left  ventricle  ; and  from  this  ven- 
tricle proceeds  the  Aorta , or  great  artery,  which 
carries  blood  to  every  part  of  the  body. 

The  heart  is  preserved  in  its  position,  1st,  by  the 
vense  cavse,  which  are  connected  to  all  the  parts  to 
which  they  are  contiguous  in  their  course ; 2d,  by 
the  vessels  which  pass  between  it  and  the  lungs, 
which  are  retained  in  a particular  position  by  the 
mediastinum  ; 3d,  by  the  aorta,  which  is  attached  to 
the  mediastinum  in  its  course  downwards,  after  mak- 
ing its  great  curve ; and  4th,  by  the  pericardium, 
which  is  attached  to  the  great  vessels  and  to  the  me- 
diastinum. By  these  different  modes  the  basis  of  the 
heart  is  fixed,  while  its  body  and  apex  are  perfectly 
free  from  attachment,  and  only  contiguous  to  the  pe- 
ricardium. 


52 


Right  Auricle. 

The  external  surface  of  the  heart,  being  formed  by 
the  pericardium.,  is  very  smooth  : under  this  surface 
a large  quantity  of  fat  is  often  found. 

The  two  auricles  are  contiguous  to  each  other  at 
the  base,  and  are  separated  by  a partition  which  is 
common  to  both. 

The  Right  Auricle  originates  from,  the  junction  of 
the  two  vense  cavge.  These  veins  are  united  at  some 
distance  behind  the  right  ventricle,*  and  are  dilated 
anteriorly  into  a sac  or  pouch,  which  is  called  the 
Sinus,  and  extends  to  the  right  ventricle,  to  which 
it  is  united. 

The  upper  part  of  this  poueh,  or  sinus,  forms  a 
point  with  indented  edges,  which  is  detached  from 
the  ventricle,  and  lies  loose  on  the  right  side  of  the 
aorta.  This  point  has  some  resemblance  to  the  ear 
of  a dog,  from  which  circumstance  the  whole  cavity 
has  been  called  auricle ; but  by  many  persons  the 
cavity  is  considered  as  consisting  of  two  portions  : the 
Auricle,  strictly  speaking  ; and  the  Sinus  Venosus , 
above  described : they  however  form  but  one  cavity. 

This  portion  of  the  heart,  or  Right  Auricle,  is  of 
an  irregular  oblong  figure.  In  its  posterior  surface, 
it  is  indented ; for  the  direction  of  the  two  cavge, 
at  their  junction,  is  not  precisely  the  same  ; but  they 
form  an  angle,  which  causes  this  indentation.  The 
anterior  portion  of  the  auricle,  or  that  which  appears 
like  a pouch  between  the  ventricle  and  the  veins,  is 
different  in  its  structure  from  the  posterior  part, 
which  is  strictly  a portion  of  the  veins.  It  consists 
simply  of  muscular  fibres,  which  are  arranged  in  fas- 
ciculi that  cover  the  whole  internal  surface  : this  is 
also  the  case  with  the  point,  or  that  part  which  is 
strictly  called  auricle. 


* In  this  description  the  heart  is  supposed  to  be  in  its  natural  position. 


53 


Right  Ventricle . 

These  fasciculi  are  denominated  Musculi  Pecti- 
nati,  from  their  resemblance  to  the  teeth  of  a comb. 

That  part  of  the  internal  surface,  which  is  formed 
by  the  septum,  is  smooth ; and  the  whole  is  covered 
by  a delicate  membrane. 

On  the  surface  of  the  septum,  below  the  middle, 
is  an  oval  depression,  which  has  a thick  edge  or 
margin  : this  is  called  the  Fossa  Ovalis.  In  the  foe- 
tal heart,  it  was  the  Foramen  Ovale,  or  aperture 
which  forms  the  communication  between  the  two 
auricles. 

Near  this  fossa  is  a large  semilunar  plait,  or  valve, 
with  its  points  and  concave  edge  uppermost,  and 
convex  edge  downwards.  It  was  described  by  Eu- 
stachius,  and,  therefore,  is  called  the  Valve  of  Eu- 
stachius. 

Anterior  to  this  valve,  and  near  the  union  of  the 
auricle  and  ventricle,  is  the  orifice  of  the  proper 
vein  of  the  heart,  or  the  conorary  vein.  This  ori- 
fice is  covered  by  another  semilunar  valve,  which  is 
sometimes  reticulated. 

The  aperture,  which  forms  the  communication  be- 
tween the  right  auricle  and  right  ventricle,  is  about 
an  inch  in  diameter,  and  is  called  ostium  venosum. 
From  its  whole  margin  arises  a valvular  ring,  or  du- 
plicature  of  the  membrane  lining  the  surface  : this 
circular  valve  is  divided  into  three  angular  portions, 
which  are  called  Valvulse  Tricuspides.  From  their 
margins  proceed  a great  number  of  fine  tendinous 
threads,  which  are  connected  to  a number  of  distinct 
portions  of  muscular  substance,  which  arise  from  the 
ventricle. 

The  right  Ventricle , when  examined  separately 
from  the  other  parts  of  the  heart,  is  rather  triangular 
in  its  figure.  It  is  composed  entirely  of  muscular 
fibres  closely  compacted  ; and  is  much  thicker  than 
the  auricle,  although  not  so  thick  as  the  other  ven- 


54 


Right  Ventricle. 

tricle.  Its  internal  surface  is  composed  of  bundles 
or  columns  of  fleshy  fibres,  which  are  of  various 
thickness  and  length.  Some  of  these  columns  arise 
from  the  ventricle,  and  are  connected  with  the  ten- 
dinous threads,  which  are  attached  to  the  margin  of 
the  tricuspid  valves : the  direction  of  them  is  from 
the  apex  of  the  heart  towards  the  base.  Others  of 
the  columns  arise  from  one  part  of  the  surface  of  the 
ventricle,  and  are  inserted  into  another  part.  A 
third  species  are  attached  to  the  ventricle  through- 
out their  whole  length,  forming  ridges  or  eminences 
on  it.  The  columns  of  the  two  last  described  species 
are  very  numerous.  They  present  an  elegant  reti- 
culated surface  when  the  ventricle  is  laid  open,  and 
appear  also  to  occupy  a considerable  portion  of  the 
cavity  of  the  heart,  which  some  of  them  run  across 
in  every  direction  near  the  apex.  They  are  all 
covered  by  a membrane  continued  from  the  auricle 
and  the  tricuspid  valves  ; but  this  membrane  appears 
more  delicate  and  transparent  in  the  ventricle  than 
it  is  in  the  auricle. 

A portion  of  the  internal  surface  of  the  ventricle, 
which  is  to  the  left,  is  much  smoother  and  less  fasci- 
culated than  the  rest : it  leads  to  the  orifice  of  the 
pulmonary  artery,  which  arises  from  it  near  the  ba- 
sis of  the  ventricle.  This  artery  is  very  conspicu- 
ous, externally,  at  the  basis  of  the  heart. 

It  is  very  evident,  upon  the  first  inspection  of  the 
heart,  that  the  valvules  tricuspides  will  permit  the 
blood  to  flow  from  the  auricle  to  the  ventricle  ; but 
must  rise  and  close  the  orifice,  and  thereby  prevent 
its  passage  back  again,  when  the  ventricle  contracts. 

The  use  of  the  tendinous  threads,  which  connect 
the  valves  to  the  fleshy  columns,  is  also  very  evi- 
dent; the  valve  is  supported  by  this  connexion, 
and  prevented  from  yielding  to  the  pressure  and 
opening  a passage  into  the  auricle.  The  blood. 


Left  Auricle . a 5 

therefore',  upon  the  contraction  of  the  ventricle,  is 
necessarily  forced  into  the  pulmonary  artery  ; the 
passage  to  which  is  now  perfectly  free.  Into  this 
artery  the  membrane  lining  the  ventricle  seems  con- 
tinued ; but  immediately  within  the  orifice  of  the 
artery  it  is  formed  into  three  semicircular  folds, 
each  of  which  adheres  to  the  surface  of  the  artery 
by  its  circumference,  while  the  edge  constituting  its 
diameter  is  loose. 1 In  the  middle  of  this  loose  edge, 
is  a small  firm  tubercle,  called  Corpusculum  Arantii,* 
which  adds  to  the  strength  of  the  valve.  Each  of 
these  valves,  by  its  connexion  with  the  artery,  forms 
a sac  or  pocket,  the  orifice  of  which  opens  forward 
towards  the  course  of  the  artery,  and  the  bottom  of 
it.  presents  towards  the  ventricle.  Blood  will,  there- 
fore, pass  from  the  ventricle  in  the  artery,  and  along 
it,  without  filling  these  sacs ; and  on  the  contrary, 
in  this  course,  will  compress  them  and  keep  them 
empty.  If  it  moves  in  the  artery  towards  the  heart, 
it  will  necessarily  fill  these  sacs,  and  press  the  se- 
micircular portions  from  the  sides  of  the  artery 
against  each  other  ; by  this  means  a partition  or  sep- 
tum, consisting  of  three  portions,  will  be  formed  be- 
tween the  artery  and  the  heart,  which  will  always 
exist  when  the  artery  compresses,  (or  acts  upon,)  its 
contents.  It  is  demonstrable,  by  injecting  wax  into 
the  artery,  in  a retrograde  direction,  that  these  valves 
do  not  form  a flat  septum,  but  one  which  is  convex 
towards  the  heart,  and  concave  towards  the  artery ; 
and  that  this  convexity  is  composed  of  three  distinct 
parts,  each  of  which  is  convex.  At  the  place  where 
these  valves  are  fixed,  the  artery  bulges  out  when 
distended  by  a retrograde  injection.  The  enlarge- 
ments thus  produced  are  called  the  Sinuses  of  Val- 
salva, after  the  anatomist  who  first  described  them. 


After  Arantius,  a professor  at  Bologna,  who  first  described  it. 


i36 


Left  Ventrical. 

The  valves  are  called  Semilunar;  and,  although  they 
are  formed  by  a very  thin  membrane,  they  are  very 
strong. 

The  Left  .'thtricle  is  situated  on  the  left  side  of  the 
basis  of  the  heart.  It  originates  from  the  junction  of 
the  four  pulmonary  veins  ; two  of  which  come  from 
each  side  of  the  thorax,  and  appear  to  form  a large 
part  of  it.  It  is  nearly  of  a cubic  form  ; but  has  also 
an  angular  portion,  which  constitutes  the  proper  au- 
ricle, that  proceeds  from  the  upper  and  left  part  of 
the  cavity,  and  is  situated  on  the  left  side  of  the  pul- 
monary artery. 

This  auricle  is  lined  by  a strong  membrane,  from 
which  the  valves  between  it  and  the  ventricle  ori- 
ginate ; but  it  has  no  fleshy  columns  or  musculi  pec- 
tinati,  except  in  the  angular  process  properly  called 
auricle. 

These  valves,  and  the  orifice  communicating  with 
the  ventricle,  resemble  those  which  have  been  al- 
ready described  between  the  right  auricle  and  ven- 
tricle ; but  with  this  difference,  that  the  valvular 
ring  is  divided  into  two  portions  only,  instead  of 
three,  which  are  called  Vulvulx  Mitrales.  The  ten- 
dinous threads,  which  are  connected  to  the  muscular 
columns,  are  also  attached  to  these  valves,  as  in  the 
ease  of  the  right  auricle. 

These  valves  admit  the  passage  of  blood  from  the 
auricle  into  the  ventricle,  but  completely  prevent  its 
return  when  the  ventricle  contracts.  One  of  them  is 
so  situated  that  it  covers  the  mouth  of  the  aorta 
while  the  blood  is  flowing  into  the  ventricle,  and 
leaves  that  orifice  open  when  the  ventricle  contracts, 
and  the  passage  to  the  auricle  is  closed. 

The  Left  Ventricle  is  situated  posteriorly,  and  to 
the  left  of  the  Right  Ventricle : its  figure  is  differ- 
ent, for  it  is  rather  conical,  and  it  is  also  longer. 

The  internal  surface  of  this  ventricle  resembles 


57 


Muscular  Fibres  of  the  Heart. 

that  of  the  right  ventricle  ; but  the  eolumnse  carneaa 
are  stronger  and  larger. 

On  the  right  side  of  this  ventricle  is  the  mouth  of 
the  aorta.  The  surface  of  the  ventricle  near  this 
opening  is  smooth  and  polished  to  facilitate  the  pas- 
sage of  the  blood. 

The  mouth  of  the  aorta  is  furnished  with  three 
semilunar  valves,  after  the  manner  of  the  pulmonary 
artery,  but  the  former  are  stronger  ; the  corpuscula 
arantii  are  better  developed  in  them.  Indeed  Mr. 
Hunter  does  not  admit  of  their  existence  in  the  pul- 
monary artery.  The  sinuses  of  Valsalva  are  about 
the  same  size  in  both  arteries. 

The  cavity  of  this  ventricle  is  supposed  to  be 
smaller  than  that  of  the  right ; but  the  amount  of  the 
difference  has  not  been  accurately  ascertained. 

This  ventricle  must  have  much  more  force  than  the 
right,  as  its  parietes  are  so  much  thicker.  Their 
thickness  often  exceeds  half  an  inch. 

The  difference  in  the  strength  of  the  two  ventricles 
probably  corresponds  with  the  difference  between  the 
extent  of  the  pulmonary  artery  and  the  aorta. 

The  thickness  of  the  septum  between  the  ventri- 
cles is  thicker  than  the  sides  or  parietes  of  the  right 
ventricle,  and  less  thick  than  those  of  the  left. 

The  muscular  fibres  of  the  heart  are  generally  less 
florid  than  those  of  the  voluntary  muscles  ; they  are 
also  more  closely  compacted  together.  The  direc- 
tion of  many  of  them  is  oblique  or  spiral  ; but  this 
general  arrangement  is  very  intricate  : it  is  such, 
however,  that  the  cavities  of  the  heart  are  lessened, 
and  probably  completely  obliterated,  by  the  contrac- 
tion of  these  fibres.* 


Mr.  Home  has  given  a precise  description  of  the  muscular  hbres  oi 
the  heart  in  his  Croonian  Lecture.  London  Philosopher!  for 

1795,  part  I.  page  215. 

VOL.  II. 


8 


58  Coronary  Vessels , $c. 

The  external  surface  of  the  heart  is  covered  by 
that  portion  of  the  pericardium  which  adheres  to  it. 
Adipose  matter  is  often  deposited  between  this  mem- 
brane and  the  muscular  surface  ; being  distributed 
irregularly  in  various  places. 

This  membrane  is  continued  from  the  surface  of  the 
ventricles  over  that  of  the  auricles.  When  it  is  dis- 
sected off  from  the  place  of  their  junction,  these 
surfaces  appear  very  distinct  from  each  other. 

The  proper  blood  vessels  of  the  heart  appear  to  be 
arranged  in  conformity  to  the  general  laws  of  the 
circulation,  and  are  very  conspicuous  on  the  surface. 
There  are  two  arteries  which  arise  from  the  aorto  im- 
mediately after  it  leaves  the  heart,  so  that  their  orifices 
are  covered  by  two  of  the  semilunar  valves.  One  of 
these  passes  from  the  aorta  between  the  pulmonary 
artery  and  the  right  auricle,  and  continues  in  a cir- 
cular course  in  the  groove  between  the  right  auricle 
and  the  right  ventricle,  and  sends  off  its  principal 
branches  to  the  right  side  of  the  heart. 

The  other  artery  of  the  heart  passes  between  the 
pulmonary  artery  and  the  left  auricle.  It  divides  into 
two  branches : one,  which  is  anterior,  passes  to  a 
groove  on  the  surface,  corresponding  to  the  septum 
between  the  two  ventricles,  and  continues  on  it  to  the 
apex  of  the  heart,  sending  off  branches  in  its  course; 
another,  which  is  posterior  and  circumflex,  passes  be- 
tween the  left  auricle  and  ventricle. 

The  great  vein  of  the  heart  opens  into  the  under 
side  of  the  right  auricle,  as  has  been  already  mention- 
ed : the  main  trunk  of  this  vein  passes  for  some  dis- 
tance between  the  left  auricle  and  ventricle.* 

* It  was  asserted  by  Vieussens  at  an  early  period,  in  the  last  century, 
and\<jon  afterwards  by  Thebesius,  a German  Professor,  that  there  were  a 
numbbypf  small  orifices  in  the  texture  of  the  heart,  which  opened  into  the 
different  >avities  or.  both  sides  of  it. 

> This  assu^ion  of  «.  fact  so  difficult  to  reconcile  with  the  general  prin- 
ciples of  the  drculation.  was  received  with  great  hesitation  : and  although 


The  Great  Vessels . 


59 


From  the  coarse  of  these  different  vessels  round 
the  basis  of  the  ventricles  of  the  heart,  they  are  ge- 
nerally called  Coronary  Vessels:  the  arteries  are 
denominated,  from  their  position,  Right  and  Left 
Coronary. 

The  nerves  of  the  heart  come  from  the  cardiac 
plexus,  which  is  composed  of  threads  derived  from 
the  intercostal  or  great  sympathetic  nerves,  and  the 
nerves  of  the  eighth  pair. 

SECTION  III. 

Of  the  Aorta , the  Pulmonary  Artery  and  Veins , 

and  the  Vense  Cavse  ; at  their  commencement . 

The  two  great  arteries,  which  arise  from  the  heart, 
commence  abruptly,  and  appear  to  be  extremely  dif- 
ferent in  their  composition  and  structure  from  the 
heart. 

They  are  composed  of  a substance,  which  has  a 
whitish  colour  and  very  dense  texture,  and  is  very 
elastic  as  well  as  firm  and  strong. 

When  the  pericardium  is  removed,  these  arteries 
appear  to  proceed  together  from  the  upper  part  of  the 
basis  of  the  heart : the  pulmonary  artery  being  placed 

it  was  confirmed  by  some  very  respectable  anatomists  of  the  last  century, 
it  was  denied  by  others.  Some  of  the  anatomists  of  the  present  day  have 
denied  the  existence  of  these  orifices,  and  some  others  have  neglected 
them  entirely. 

The  subject  has  lately  been  brought  forward  in  the  London  Philoso- 
phical Transactions  for  1798,  Part  I by  a very  respectable  anatomist,  Mr. 
Abernethy,  who  states  that  he  has  often  passed  a coarse  waxen  injection 
from  the  proper  arteries  and  veins  of  the  heart  into  all  the  cavities  of  that 
organ,  and  particularly  into  the  Left  Ventricle.  But  it  was  only  in  sub- 
jects with  diseased  lungs  that  this  was  practicable. 

The  existence  of  this  communication  between  the  coronary  vessels  and 
the  great  cavities  of  the  heart  seems  therefore  to  be  proved.  The  easy 
demonstration  in  such  subjects  is  ingeniousl)  referred  by  Mr.  Abernethv. 
to  the  obstruction  of  the  circulation  in  the  lungs  : and  he  regards  the  com- 
munication as  a provision  enabling  the  coronary  vessels  to  unload  them- 
selves, when  the  coronary  vein  cannot  dtscha-ge  freely  into  the  right 
auricle. 


60  Pulmonary  Artery  and  Veins  and  Vense  Cause. 

to  the  left  of  the  aorta  with  the  left  auricle  on  the  left 
side  of  it,  and  the  right  auricle  on  the  right  side  of 
the  aorta.  The  pulmonary  artery  arises  from  the 
most  anterior,  and  left  part  of  the  basis  of  the  right 
ventricle,  and  proceeds  obliquely  backwards  and  up- 
wards ; inclining  gradually  to  the  left  side  for  about 
eighteen  or  twenty  lines  ; when  it  divides  into  two 
branches  which  pass  to  the  two  lungs. 

The  aorta  arises  from  the  left  ventricle,  under  the 
origin  of  the  pulmonary  artery,  and  immediately  pro- 
ceeds to  the  right,  covered  by  that  vessel,  until  it 
mounts  up  between  it  and  the  right  auricle  : it  then 
forms  a great  curve,  or  arch,  which  turns  backward 
and  to  the  left,  to  a considerable  distance  beyond  the 
pulmonary  artery.  In  this  course,  it  crosses  the 
right  branch  of  the  pulmonary  artery  ; and,  turning 
down  in  the  angle  between  it  and  the  left  branch, 
takes  a position  on  the  left  side  of  the  spine. 

The  course  of  this  artery,  from  its  commencement 
at  the  ventricle,  to  the  end  of  the  great  curve  or 
arch,  is  extremely  varied. 

The  uppermost  part  of  the  curve  is  in  the  bottom 
of  the  chamber  formed  by  the  separation  of  the  la- 
mina of  the  mediastinum  when  they  join  the  first 
rib  on  each  side. 

From  this  part  of  the  curve  three  large  branches 
go  off,  viz.  one,  which  soon  divides  into  the  carotid 
and  the  subclavian  arteries  of  the  right  side ; a se- 
cond, somewhat  smaller,  which  is  the  left  carotid  ; 
and  a third,  which  is  the  left  subclavian  artery. 

When  the  heart  and  its  great  vessels  are  viewed 
from  behind,  (after  they  have  all  been  filled  with 
injection  ; and  the  pericardium,  mediastinum,  and 
windpipe  have  been  removed,)  the  aorta  appears 
first,  descending  behind  the  other  vessels ; the  pul- 
monary artery  then  appears,  dividing  so  as  to  form 
an  obtuse  angle  with  its  two  great  branches,  each  of 


Pulmonary  Artery  and  Veins  and  Verne  Cavse.  61 

which  divides  again  before  it  enters  the  lung  to  which 
it  is  destined. 

Under  the  main  trunk  of  the  pulmonary  artery  is 
the  left  auricle  : its  posterior  surface  is  nearly  of  a 
square  form,  and  each  of  the  pulmonary  veins  pro- 
ceeds from  one  of  its  angles.  These  veins  ramify  in 
the  substance  of  the  lungs,  at  a very  short  distance 
from  the  auricle  : the  two  uppermost  of  them  are  si- 
tuated rather  anterior  to  the  branches  of  the  pulmo- 
nary artery. 

In  this  posterior  view,  the  pulmonary  vessels  of 
the  right  side  cover  a great  part  of  the  right  auricle, 
as  it  is  anterior  to  them.  The  lower  portion  of  the 
auricle,  with  the  termination  of  the  inferior  cava,  is 
to  be  seen  below  them.  Above  them  the  superior 
cava  appears  ; and  in  that  part  of  it  which  is  imme- 
diately above  the  right  branch  of  the  pulmonary  ar- 
tery, is  the  orifice  of  the  vena  azygos. 

In  its  natural  situation  in  the  thorax,  the  superior 
cava  is  connected  by  cellular  membrane  to  the  right 
lamen  of  the  mediastinum,  and  supported  by  it.  At 
a small  distance  below  the  upper  edge  of  the  ster- 
num, it  receives  the  trunk  formed  by  the  left  subcla- 
vian and  internal  jugular  vein,  which  passes  oblique- 
ly across  the  sternum  below  its  inner  edge,  in  the 
upper  space  between  the  lamina  of  the  mediastinum. 


CHAPTER  III. 


OF  THE  TRACHEA  AND  THE  LUNGS. 

Although  the  principal  part  of  the  windpipe  is 
situated  in  the  neck  above  the  cavity  of  the  thorax., 
it  is  so  intimately  connected  with  the  lungs,  that  it  is 
necessary  to  describe  them  together, 

SECTION  I. 

Of  the  Trachea. 

Trachea  is  the  technical  name  for.  the  windpipe, 
or  tube  which  passes  from  the  larynx  to  the  lungs. 

This  tube  begins  at  the  lower  edge  of  the  cricoid 
cartilage,  and  passes  down  the  neck  in  front  of  the 
oesophagus  as  low  as  the  third  dorsal  vertebra,  when 
it  divides  into  two  branches  called  Bronchia , one  of 
which  goes  to  the  right  and  the  other  to  the  left  lung 
and  ramifies  very  minutely  in  them. 

There  is  in  its  structure  a number  of  flat  cartila- 
ginous rings  placed  at  small  distances  from  each  oth- 
er, the  edges  of  which  are  connected  by  membrane 
so  that  they  compose  a tube. 

These  cartilaginous  rings  are  not  complete,  for  they 
do  not  form  more  than  three-fourths  or  four-fifths  of 
a circle  ; but  their  ends  are  connected  by  a mem- 
brane which  forms  the  posterior  part  of  the  tube. 

They  are  not  alike  in  their  size  or  form  ; some  of 
them  are  rendered  broader  than  others,  by  the  union 
of  two  or  three  rings  with  each  other,  as  the  upper- 
most. The  lowermost  also  is  broad,  and  has  a form 
which  is  accommodated  to  the  bifurcation  of  the  tube. 
Their  number  varies,  in  different  persons  from  fif- 
teen to  twenty. 


63 


Structure  of  the  Trachea . 

These  rings  may  be  considered  as  forming  a part 
of  the  first  proper  coat  of  the  trachea ; which  is  com- 
posed of  them,  and  of  an  elastic  membrane  that  occu- 
pies all  the  interstice  between  them  ; so  that  the  car- 
tilages may  be  regarded  as  fixed  in  this  membrane. 

A similar  arrangement  of  rings  exists  in  the  great 
branches  of  the  bronchia ; but  after  they  ramify  in 
the  lungs,  the  cartilages  are  no  longer  in  the  form  of 
rings  : they  are  irregular  in  their  figures,  and  are  so 
arranged  in  the  membrane  that  they  keep  the  tube 
completely  open.  These  portions  of  cartilage  do  not 
continue  throughout  the  whole  extent  of  the  ramifi- 
cations ; for  they  become  smaller,  and  finally  disap- 
pear, while  the  membranous  tube  continues  without 
them,  ramifying  minutely,  and  probably  forming  the 
air  cells  of  the  lungs. 

This  membrane  is  very  elastic  : the  lungs  are  very 
elastic  also  ; and  it  is  probable  that  their  elasticity 
is  derived  from  this  membrane. 

On  the  inside  of  this  coat  of  the  trachea  is  an  ar- 
rangement of  muscular  fibres,  which  may  be  called 
a muscular  coat.  It  is  best  seen  by  peeling  off  or 
removing  the  internal  coat  to  be  next  described. 

On  the  membranous  part  of  the  trachea,  where  the 
cartilaginous  rings  are  deficient,  these  muscular 
fibres  run  evidently  in  a transverse  direction : in  the 
spaces  between  the  cartilages  their  direction  is  lon- 
gitudinal. There  is  some  reason  to  doubt  whether 
these  longitudinal  fibres  are  confined  altogether  to 
the  spaces  between  the  cartilaginous  rings,  and  at- 
tached only  to  their  edges,  because  their  is  a fleshy 
substance  on  the  internal  surface  of  the  rings,  which 
appears  to  be  continued  from  the  spaces  between 
them. 

The  internal  coat  of  the  trachea  is  a thin  and  de- 
licate membrane,  perforated  with  an  immense  num- 


64  Black  Glands  of  the  Bronchise. 

ber  of  small  foramina;  which  are  the  orifices  of  mu- 
cous ducts. 

On  the  surface  of  this  membrane  there  is  an  ap- 
pearance of  longitudinal  fibres  which  are  not  distri- 
buted uniformly  over  it,  but  run  in  fasciculi  in  some 
places,  and  appear  to  be  deficient  in  others.  These 
fasciculi  are  particularly  conspicuous  in  the  ramifica- 
tions of  the  bronchia  in  the  lungs. 

On  the  posterior  membranous  portion  of  the  tra- 
chea, where  the  cartilages  are  deficient,  a consider- 
able number  of  small  glandular  bodies  are  placed, 
which  are  supposed  to  communicate  with  the  mucous 
ducts  that  open  on  the  internal  surface.  If  these 
bodies  are  removed  from  the  external  surface  of  this 
portion,  and  the  muscular  fibres  are  also  removed 
from  the  internal,  a very  thin  membrane  only  re- 
mains, which  is  very  different  from  that  which  is  left 
between  the  rings,  when  the  fleshy  substance  is  re- 
moved from  that  situation. 

The  reason  of  the  deficiency  in  the  rings,  at  this 
posterior  part,  is  not  very  obvious.*  It  continues 
in  the  bronchia  until  the  form  of  their  cartilages  is 
changed  in  the  lungs : if  it  were  only  to  accommo- 
date the  oesophagus,  during  the  passage  of  food, 
there  would  be  no  occasion  for  its  extension  to  the 
bronchia. 

At  the  bifurcation  of  the  trachea,  and  on  the 
bronchia,  are  a number  of  black  coloured  bodies, 
which  resemble  the  lymphatic  glands  in  form  and 
texture.  They  continue  on  the  ramifications  of  the 
bronchia  some  distance  into  the  substance  of  the 
lungs.  Their  number  is  often  very  considerable ; 
and  they  vary  in  size  from  three  or  four  lines  in  dia- 

* Doctor  Physic  has  advanced  the  opinion  that  it  enables  a person  to  ex- 
pel the  raucous  of  the  lungs  by  contracting  the  size  of  the  trachea,  and  con- 
sequently increasing  the  velocity  or  impetus  of  the  air.— Ed. 


65 


Root  of  the  Lungs. 

meter  to  eighteen  or  twenty.  As  lymphatic  vessels 
have  been  traced  to  and  from  them  during  their  course 
to  the  thoracic  duct,  they  are  considered  as  lympha- 
tic glands. 

SECTION  II. 

Of  the  Lungs. 

There  are  two  of  these  organs:  each  of  which  oc- 
cupies one  of  the  great  cavities  of  the  thorax. 

When  placed  together,  in  their  natural  position, 
they  resemble  the  hoof  of  the  ox,  with  its  back  part 
forward  ; but  they  are  at  such  a distance  from  each 
other,  and  of  such  a figure,  that  they  allow  the  medi- 
astinum and  heart  to  intervene;  and  they  cover  every 
part  of  the  heart  anteriorly,  except  a small  portion 
at  the  apex. 

Each  lung  fills  completely  the  cavity  in  which  it 
is  placed,  and  every  part  of  its  external  surface  is  in 
contact  with  some  part  of  the  internal  surface  of  the 
cavity ; but  when  in  a natural  and  healthy  state,  it  is 
not  connected  with  any  part  except  the  lamina  of  the 
mediastinum.  One  great  branch  of  the  trachea  and 
of  the  pulmonary  artery  passes  from  the  mediastinum 
to  each  lung,  and  enters  it  at  a place  which  is  rather 
nearer  to  the  upper  rib  than  to  the  diaphragm,  and 
much  nearer  to  the  spine  than  the  sternum  : at  this 
place  also  the  pulmonary  veins  return  from  the  lungs 
to  the  heart. 

These  vessels  are  enclosed  in  a membrane,  which 
is  continued  over  them  from  the  mediastinum,  and 
extended  from  them  to  the  lung.  Thus  covered, 
they  constitute  what  has  been  called  the  Root  of  the 
Lung. 

When  their  covering,  derived  from  the  mediasti- 
num, is  removed,  the  situation  of  these  vessels  ap- 
pears to  be  such  that  the  bronchia  are  posterior, 

Vol.  ii.  9 


66 


Colour  of  the  Lungs. 

the  branches  of  the  pulmonary  artery  are  rather  above 
and  before,  and  the  veins  below  and  before  them. 

Each  of  these  vessels  ramifies  before  it  enters  into 
the  substance  of  the  lungs:  the  bronchia  and  the 
branches  of  the  pulmonary  artery  send  each  a large 
bianch  downward  to  the  inferior  part  of  the  lungs, 
from  which  the  lower  pulmonary  veins  pass  in  a di- 
rection nearly  horizontal.  In  general,  each  of  the 
smaller  ramifications  of  the  bronchia  in  the  lungs  is 
attended  by  an  artery  and  a vein. 

Each  lung  is  divided,  by  very  deep  fissures,  into 
portions  which  are  called  Lobes.  The  right  lung  is 
composed  of  three  of  these  lobes,  and  the  left  lung 
of  two. 

The  lungs  are  covered  as  has  been  already  stated, 
with  the  reflected  portion  of  the  pleura  continued 
from  the  mediastinum,  which  is  very  delicate  and  al- 
most transparent.  They  have,  therefore,  a very 
smooth  surface,  which  is  kept  moist  by  exudation 
from  the  arteries  of  the  membrane. 

The  Colour  of  the  Lungs  is  different  in  different 
subjects.  In  children  they  are  of  a light  red  colour; 
in  adults  they  are  often  of  a light  grey  ; owing  to 
the  deposition  of  a black  pigment  in  the  substance 
immediately  under  the  membranes  which  form  their 
external  surface.  Their  colour  is  often  formed  by  a 
mixture  of  red  and  black.  In  this  case  they  are  more 
loaded  with  blood,  and  the  vessels  of  the  internal 
membranes  being  distended  with  it,  the  red  colour 
is  derived  from  them. 

The  black  pigment  sometimes  appears  in  round 
spots  of  three  or  four  lines  in  diameter  : under  the  ex- 
ternal membrane  it  is  often  in  much  smaller  portions, 
and  sometimes  is  arranged  in  lines  in  the  interstices 
of  the  lobuli,  to  be  hereafter  mentioned.  It  is  also 
diffused  in  small  quantities  throughout  the  substance 
of  the  lungs. 


Structure  of  the  Lungs . 67 

The  source  of  this  substance,  and  the  use  of  it,  are 
unknown. 

The  lungs  are  of  a soft  spongy  texture  ; and,  in 
animals  that  have  breathed,  they  have  always  a con- 
siderable quantity  ol  air  in  them. 

They  consist  of  cells,  which  communicate  with  the 
branches  of  the  trachea  that  ramify  through  them  in 
every  part.  These  cells  are  extremely  small,  and 
the  membranes  which  compose  them  are  so  thin  and 
delicate  that  if  they  are  all  filled  by  an  injection  of 
wax,  thrown  into  the  trachea,  the  whole  cellular 
part  of  the  lung  will  appear  like  a mass  of  wax.  If 
a corroded  preparation  be  made  of  a lung  injected 
in  this  manner  with  force,  the  wax  will  appear  like 
a concretion. 

These  effects  of  injections  prove  that  the  membranes 
of  which  the  cells  are  formed  are  very  thin  ; and,  of 
course,  that  their  volume  is  very  small  when  compar- 
ed with  the  capacity  of  the  cells. 

In  those  corroded  preparations,  in  which  the  ra- 
mifications of  the  broncnia  are  detached  from  the  wax 
of  the  cells,  these  ramifications  become  extremely 
small  indeed. 

If  the  lungs  of  the  human  subjects,  or  of  animals 
of  similar  construction,  be  examined  when  they  are 
inflated,  their  cellular  structure  will  be  very  obvious, 
although,  their  cells  are  so  small  that  they  cannot 
commonly  be  distinguished  by  the  naked  eye.  Each 
of  the  extreme  ramifications  of  the  bronchia  appears 
to  be  surrounded  by  a portion  of  this  cellular  sub- 
stance, which  is  gradually  distended  when  air  is  blown 
into  the  ramification. 

This  celiular  substance  is  formed  into  small  por- 
tions of  various  angular  figures,  which  are  denomi- 
nated Lobuli : these  can  be  separated  to  a consider- 
able extent  from  each  other.  They  are  covered  by 
the  proper  coat  of  the  lungs,  which  is  extremely  de= 


68 


Structure  of  the  Lungs. 

licate,  and  closely  connected  to  the  general  covering 
derived  from  the  pleura.  Between  the  lobuli,  where 
they  are  in  contact  with  each  other,  there  is  a por- 
tion of  common  cellular  substance,  which  is  easily 
distinguished  through  the  membrane  covering  the 
lungs.  This  is  very  distinct  from  the  cellular  struc- 
ture which  communicates  with  the  ramifications  of 
the  bronchia,  and  contains  air  ; for  it  has  no  com- 
munication with  the  air,  unless  the  proper  coat  of 
the  lungs  be  ruptured.  If  a pipe  be  introduced  by 
* a puncture  of  the  external  coat  of  the  lungs,  and 
this  interstitial  cellular  membrane  be  inflated,  it  will 
compress  the  lobuli.  This  cellular  membrane  is  al- 
ways free  from  adipose  matter : it  may  be  easily  ex- 
amined in  the  lungs  of  the  bullock. 

Upon  the  membranes  which  compose  the  air  cells, 
the  pulmonary  artery  and  vein  ramify  most  minutely; 
and  it  seems  to  have  been  proved  within  the  last  thirty 
years,  by  the  united  labours  of  chemists  and  physio- 
logists, that  the  great  object  of  respiration  is  to  effect 
a chemical  process  between  the  atmospheric  air,  when 
taken  into  the  air  cells,  and  the  blood  which  circu- 
lates in  these  vessels. 

In  addition  to  the  blood  vessels  which  thus  pass 
through  the  substance  of  the  lungs,  there  are  several 
smaller  arteries  denominated  Bronchial , which  arise 
either  from  the  upper  intercostal,  or  from  the  aorta 
itself:  they  pass  upon  the  bronchia,  and  are  distri- 
buted to  the  substance  of  the  lungs.  The  veins 
which  correspond  with  these  arteries  terminate  ulti- 
mately in  the  vena  azygos. 

The  nerves  of  the  lungs  are  small  in  proportion  to 
the  bulk  of  these  organs.  They  are  derived  princi- 
pally from  the  par  vagum  and  the  intercostal  nerves. 

The  elasticity  of  the  air  cells  of  the  lungs  and  of 
the  ramifications  of  the  bronchia  which  lead  to  them, 
appears  by  their  rapid  contraction  after  distention, 


69 


The  Thorax  of  the  Foetus. 

and  by  the  force  with  which  they  expel  the  air  which 
is  used  to  inflate  them  when  taken  out  of  the  thorax. 

The  Thorax  of  the  Foetus. 

In  the  cavity  between  the  lamina  of  the  medias- 
tinum, where  they  approach  each  other  from  the  first 
ribs,  is  situated  a substance  which  is  denominated 
the 

Thymus  Gland. 

This  substance  gradually  diminishes  after  birth,  so 
that  in  the  adult  it  is  often  not  to  be  found  : and  when 
it  exists  it  is  changed  in  its  texture,  being  much  firmer, 
as  well  as  greatly  diminished. 

In  the  foetus  it  is  of  a pale  red  colour  ; and  during 
infancy  it  has  a yellowish  tinge.  It  generally  ex- 
tends from  the  thyroid  gland,  or  a little  below  it,  to 
the  pericardium.  From  its  superior  portion  two  la- 
teral processes  are  extended  upwards  : below,  it  is 
formed  into  two  lobes,  which  lie  on  the  pericardium. 

If  an  incision  be  made  into  its  substance,  a fluid 
can  be  pressed  out,  which  has  a whitish  colour,  and 
coagulates  upon  the  addition  of  alcohol. 

Although  it  is  called  a gland , no  excretory  duct 
has  ever  been  found  connected  with  it. 

The  blood  vessels  of  this  body  are  derived  from 
the  thyroid  branches  of  the  subclavians,  from  the  in- 
ternal mammaries,  and  the  vessels  of  the  pericardium 
and  mediastinum. 

The  Heart , 

And  the  great  arteries  which  proceed  from  it,  have 
some  very  interesting  peculiarities  in  the  foetus. 

In  the  septum  between  the  two  auricles,  is  a fora- 
men of  sufficient  size  to  permit  the  passage  of  a large 
quill,  which  inclines  to  the  oval  form,  with  its  long- 
est diameter  vertical  when  the  body  is  erect.  On 
the  left  side  of  the  septum,  a valve,  formed  by  the 
lining  membranes,  is  connected  to  this  foramen  ; and 


70 


The  Thorax  of  the  Foetus. 

allows  a free  passage  to  a fluid  moving  from  the  right 
auricle  to  the  left,  but  prevents  the  passage  of  a fluid 
from  the  left  to  the  right.  This  structure  is  evidently 
calculated  to  allow  some  of  the  blood  which  flows 
into  the  right  auricle  from  the  two  venae  cavse  to 
pass  into  the  left  auricle  of  the  heart  instead  of  going 
into  the  right  ventricle.  As  the  contents  of  the  left 
auricle  pass  into  the  left  ventricle,  and  from  thence 
into  the  aorta,  it  is  obvious  that  the  blood,  which 
passes  from  the  right  auricle  into  the  left  through 
this  foramen,  must  be  transmitted  from  the  sys- 
tem of  the  vena  cava  to  the  system  of  the  aorta 
without  going  through  the  lungs,  as  it  must  necessa- 
rily do  in  subjects  who  do  not  enjoy  the  foetal  struc- 
ture. 

The  Pulmonary  Artery  and  the  Aorta 

Have  a communication  in  the  foetus,  which  is  very 
analogous  to  the  communication  between  the  auricles 
of  the  heart. 

From  the  pulmonary  artery,  where  it  divides  into 
the  two  great  branches,  another  large  branch  conti- 
nues, in  the  direction  of  the  main  trunk,  until  it  joins 
the  aorta ; with  which  it  communicates  at  a small 
distance  below  the  origin  of  the  left  subclavian  artery. 
In  the  young  subject  that  has  never  respired,  it  ap- 
pears as  if  the  pulmonary  artery  was  continued  into 
the  aorta,  and  sent  off'  in  its  course,  a branch  on  each 
side,  much  smaller  than  itself,  to  each  lung.  In 
subjects  that  have  lived  a few  days,  these  branches 
to  the  lungs  are  much  larger ; and  then  the  main 
pulmonary  artery  appears  to  have  divided  into  three 
branches : one  to  each  lung,  and  one  to  the  aorta ; 
but  that  which  continues  to  the  aorta  is  larger  than 
either  of  the  others. 

In  the  course  of  time,  however,  this  branch  of  the 
aorta  is  contracted,  so  that  no  fluid  passes  through  it; 


General  Observations. 


71 


and  it  has  the  appearance  of  a ligament,  in  which 
slate  it  remains. 

The  course  of  the  blood  from  the  right  ventricle, 
through  the  pulmonary  artery,  to  the  aorta  below  its 
curve,  is  more  direct  than  that  from  the  left  ventricle 
to  the  same  spot,  through  the  aorta  at  its  commence- 
ment. The  column  of  blood  in  the  aorta  below  its 
curve  is  evidently  propelled  by  the  force  of  both  ven- 
tricles : and  this  circumstance,  although  it  seems  to 
proceed  merely  from  the  state  of  the  foetal  lungs,  is 
particularly  calculated  for  the  very  extensive  circula- 
tion which  the  foetus  carries  on,  by  means  of  the  um- 
bilical arteries  and  vein  in  the  placenta. 

The  Lungs  of  the.  Foetus 

Differ  greatly  from  those  of  the  adult.  They  appear 
solid,  as  if  they  were  composed  of  the  parenchymatous 
substance  which  constitutes  the  matter  of  glands, 
rather  than  the  light  spongy  substance  of  the  lungs 
of  adults.  They  differ  also  in  colour  from  the  lungs 
of  older  subjects,  being  of  a dull  red. 

They  have  greater  specific  gravity  than  water ; 
but  if  air  be  once  inspired,  so  much  of  it  remains  in 
them  that  they  ever  afterwards  float  in  that  fluid. 

The  nature  of  the  process  of  respiration,  and  its  ef- 
fects upon  the  animal  economy,  particularly  upon 
the  action  of  the  heart,  appear  to  be  much  better  un- 
derstood at  this  time  than  they  were  before  the  dis- 
covery of  the  composition  of  the  atmosphere,  by  Dr. 
Priestly  and  by  Mr.  Scheele.  The  publications  upon 
this  subject,  which  have  appeared  since  that  period, 
viz.  1774,  are  therefore  much  more  interesting  to 
the  student  of  medicine  than  those  which  preceded 
them.  Two  of  these  publications  ought  to  be  parti- 
cularly noticed  by  him : viz,  an  essay,  by  Dr.  Ed- 
ward Goodwyn,  entitled,  “ The  Connexion  of  life 


72  Cases  of  Malformation. 

with  respiration;”  and — the  “ Physiological  Re- 
searches of  M.  Bichat  upon  Life  and  Death.  Part 
Second.* 

The  general  doctrines  respecting  the  oxygenation  or 
decarbonation  of  the  blood,  and  the  absolute  necessi- 
ty that  it  should  take  place  to  a certain  degree  in  or- 
der to  preserve  life,  are  confirmed  by  a number  of 
cases  of  malformation  of  the  heart  or  the  great  ves- 
sels, in  which  the  structure  was  such  that  a consider- 
able portion  of  venous  blood  passed  from  the  right 
side  of  the  heart  to  the  aorta,  without  going  through 
the  lungs.  In  these  different  cases,  notwithstanding 
the  structure  was  somewhat  varied,  the  symptoms 
produced  were  very  much  alike  ; differing  in  the  re- 
spective patients  in  degree  only,  and  not  in  kind. 

The  symptoms  indicating  this  structure  are  blue 
colour  of  the  face,  (such  as  generally  accompanies 
suffocation.)  extending  more  or  less  over  the  whole 
body,  and  particularly  apparent  under  the  nails  of 
the  fingers  and  toes  ; anxiety  about  the  region  of  the 
heart;  palpitation;  laborious  respiration;  sensations 
of  great  debility,  &c.:  all  of  which  are  greatly  aggra- 
vated by  muscular  exertion.  These  effects  have  gen- 
erally appeared  to  be  proportioned  to  the  quantity 
of  venous  blood  admitted  into  the  aortic  system. t 
When  these  appearances  take  place  immediately 
after  birth,  it  is  probable  that  they  depend  entirely 
upon  malformation  of  the  heart  or  great  vessels;  but 
when  they  commence  at  a subsequent  period,  they  are 

* The  student  will  derive  much  information  respecting  the  publications 
on  this  subject,  prior  to  1804,  from  Dr.  Bostock’s  Essay  on  Respiration — 
Since  the  publication  of  that  essay  several  interesting  papers  on  respira- 
tion have  appeared,  viz.  Two  memoirs  by  the  late  Abbe  Spalanzani  ; — 
“ An  Enquiry  into  the  Changes  induced  on  Atmospheric  Air  by  the  Ger- 
mination of  Seeds,”  &c.  by  Ellis  ; — two  very  important  communications  by 
Messrs.  Allen  and  Pepys  in  the  Transactions  of  the  Royal  Society  of  Lon- 
don for  1808  and  1809; — and  “ Further  Enquiries  into  the  Changes  induced 
on  Atmospheric  Air.”  Also  by  Ellis. 

f Cases  of  this  kind  are  related  in  several  of  the  periodical  publications 
on  medical  subjects.  Two  of  them  were  described  by  the  late  Dr.  Wil- 
liam Hunter  in  the  sixth  volume  of  Medical  Observations  and  Enquiries, 
by  a Society  of  Physicians  in  London  ; one,  (quoted  by  Dr.  Goodwyn,)  is 
in  the  Observationes  Anatomicse  of  Sandifort  ; and  another,  by  Dr  J.  S. 
Dorsey,  has  lately  been  published  in  the  first  oumber  of  the  New  England 
Journal  of  Medicine  and  Surgery. 


Cases  of  Malformation.  73 

commonly  the  effect  of  a diseased  alteration  in  the 
lungs.  They  sometimes  occur  near  the  termination 
of  fcital  cases  of  pneumonia  or  catarrh  ; but  a . diffe- 
rent cause,  which  has  not  latterly  been  suspected, 
appears  to  have  produced  them  in  the  following  case 
related  by  Dr.  Marcet,  in  the  first  volume  of  the 
Edinburgh  Medical  and  Physical  Journal. 

The  blue  colour  occurred  in  a young  woman,  twen- 
ty-one years  of  age,  in  whom  it  had  never  been  ob- 
served before. — It  came  on  during  an  affection  of 
the  breast,  and  was  attended  with  great  prostration 
of  strength  and  difficulty  of  breathing  ; as  well  as 
cough,  oedema  of  the  hands  and  feet,  and  several 
other  symptoms.  About  seven  weeks  after  the  com- 
mencement of  these  symptoms  she  died  $ when  it 
was  ascertained  by  dissection,  that  there  was  no 
unnatural  communication  whatever  between  the  ca- 
vities of  the  heart,  and  that  its  valves  were  all  in 
a perfect  and  natural  state . The  lungs  were  free 
from  tubercles,  or  any  other  appearance  of  disease. 
Their  substance  seemed  more  compact  than  usual, 
especially  the  left  lung,  although  it  did  not  sink  in 
water  5 but  they  adhered  every  where  to  the  inner 
surface  of  the  thorax,  to  the  diaphragm , and  to  the 
pleura  covering  the  pericardium. — This  case  is  the 
more  remarkable,  because  numberless  instances 
have  occurred  in  which  very  large,  portions  of  the 
external  surface  of  the  lungs  have  been  found  upon 
dissection  to  adhere  to  the  internal  surface  of  the 
thorax  without  the  occurrence  of  such  symptoms 
during  life. 

It  may  be  inferred,  from  a statement  published  by  M. 
Dupuytren,  in  a late  volume  of  the  Proceedings  of 
the  National  Institute  of  France,  that  the  oxygena- 
tion or  decarbonation  of  the  blood  is  much  affected, 
in  respiration,  by  an  influence  exercised  by  the 
nerves  which  are  appropriated  to  the  lungs.  From 
his  account  it  appears,  that  although  the  complete 
division  of  the  eighth  pair  of  nerves  produces  death 
after  some  time  ; yet  in  the  horse  whose  nerves  are 
thus  divided,  life  continues,  and  respiration  goes 
an,  from  half  an  hour  to  ten  hours  ; but  his  arterial 
blood  is  in  a state  of  great  disoxygenation.  or  corbo- 
nation,  during  this  time.  This  fact  is  more  rem sxka- 

Vol,  II„  W 10 


74  Effects  of  Venous  Blood  on  the  Heart. 


hie,  because  venous  blood,  contained  in  a bladder 
exposed  to  the  open  air,  will  become  oxygenated  or 
decarbonated. 

It  is  also  asserted  in  another  Memoir,  read  to  the 
National  Institute  by  Dr.  J.  M.  Provem^al,  that  ani- 
mals in  whom  the  eighth  pair  of  nerves  has  been 
divided,  do  not  consume  so  much  oxygen,  or  produce 
so  much  carbonic  acid,  by  a considerable  degree,  as 
they  did  before  the  division  of  these  nerves  ; and 
that  their  temperature  is  considerably  reduced.* 

The  fact,  that  venous  blood  occasions  death,  when  it  is 
admitted  into  the  left  ventricle  of  the  heart,  and  the 
aorta,  is  truly  important.  Dr.  Goodwin  explained  it 
by  suggesting  that  this  blood  was  not  sufficiently  sti- 
mulating to  produce  the  necessary  excitement  of  the 
heart ; but  on  this  occasion  one  of  his  friends  propo- 
sed to  him  the  following  question:  Why  does  venous 
blood  affect  the  left  side  of  the  heart  in  this  injurious 
manner,  when  it  appears  to  exert  no  noxious  effects 
whatever  on  the  right  side  of  tbatorgan  ? His  reply 
may  be  seen  in  a note  at  the  8 2d  page  of  his  Essay, 
in  the  first  edition.  Bichat  has  offered  a solution 
which  completely  resolves  this  difficulty,  viz.  “ The 
effect  of  Venous  blood  upon  the  heart  is  produced  by 
the  presence  of  this  blood  in  the  proper,  or  coronary 
arteries  of  that  organ,  and  not  in  its  great  cavities.” 
For  the  animation  of  the  heart,  like  that  of  the  other 
parts  of  the  body,  depends  upon  the  state  of  the  blood 
in  the  arteries  which  penetrate  its  fexture.t  And 
while  the  heart  acts,  the  blood  of  the  coronary  arte- 
ries will  be  the  same  with  that  of  the  left  ventricle. 
See  Bichat’s  Researches,  P.  II.  art.  6.  § 2. 

The  French  Anatomists  appear  to  entertain  some  pecu- 
liar opinions  respecting  the  course  of  the  blood  in 
the  foetus,  which  have  a particular  relation  to  the  sub- 
ject last  mentioned.  Winslow,  who  paid  great  at- 
tention to  the  valve  of  Eustachius  in  the  right  auricle 
of  the  heart,  was  of  opinion,  that  this  valve  was  cal- 

These  Memoirs  are  republished  in  the  Eclectic  Repertory  of  Phila- 
delphia for  April  and  October,  1811. 

f It  is  probable  that  the  contents  of  the  great  cavities  of  (.lie  heart  have 
no  more  effect  upon  its  animation  than  the  contents  of  the  stomach  and. 
bowels  love  upon  the  animation  of  those  organs,. 


Sentiments  of  Sabatier , fyc.  75 

dilated  for  some  important  purpose  in  the  fetal  eco- 
nomy.*1 Although  his  hypothesis  respecting  its  par- 
ticular use  has  not  been  retained  by  his  countrymen, 
many  of  them  have  adopted  his  general  sentiment  $ 
and  among  others  Sabatier.  That  learned  anatomist 
believed  that  this  valve,  in  the  fetal  state,  serves 
to  direct  the  blood  of  the  inferior  cava , after  its  ar- 
rival in  the  right  auricle , through  the  foramen  ovale 
into  the  left  auricle ; while  the  blood  of  the  upper 
cava  passes  directly  into  the  right  ventricle.  His 
opinion  seems  to  be  supported  to  a certain  degree. 

1.  By  the  direction  in  which  the  two  columns  of 
blood  enter  the  auricle  from  the  two  vense  cavse. 

2.  By  the  position  of  the  Eustachian  valve. 

3.  By  the  foramen  ovale,  when  its  valve  is  com- 
. plete  ; as  the  passage  through  it,  from  the  right  to  the 

left,  is  at  that  time  oblique,  and  from  below  upwards. 

The  theory  of  Sabatier  appears  to  be  this : the  um- 
bilical vein  brings  from  the  placenta  blood  which  has 
a quality  essential  to  the  animation  of  the  fetus.  If 
there  were  no  particular  provision  to  the  contrary,  a 
large  portion  of  this  blood,  after  passing  from  the 
umbilical  vein  by  the  inferior  cava  into  the  right 
• auricle  of  the  heart,  would  proceed  by  the  right  ven- 
tricle, though  the  pulmonary  pretry  and  arterial  ca- 
nal, into  the  aorta,  below  the  origins  of  the  carotid 
and  subclavian  arteries  ; and  consequently  none  of 
it  would  pass  to  the  head  and  upper  extremities,  but 
a considerable  part  would  return  again  by  the  umbi- 
lical arteries  to  the  placenta,  without  circulating 
through  the  body  : while  on  the  other  hand,  the 
blood  which  passed  by  the  carotid  and  subclavian 
arteries  to  the  head  and  upper  extremities,  return- 
ing from  them  to  the  heart  by  the  superior  cava, 
might  pass  from  the  right  auricle  to  the  left  auricle 
and  ventricle  and  the  aorta,  and  so  to  the  head  and 
upper  extremities  again,  without  passing  through 
the  placenta.  But  by  means  of  tins  valve,  the  blood 
of  the  Sower  cava,  and  of  course  of  the  umbilical 
vein,  is  directed  to  the  left  auricle  and  ventricle 
and  the  aorta,  by  which  a considerable  portion  of 
it  will  necessarily  pass  to  the  head  and  upper  ex- 
tremities : while  the  blood  which  returns  from  these 

See  Memoirs  of  the  Academy  of  Sciences  for  1717  and  1725. 


76 


Sentiments  of  Sabatier , 

parts  by  the  superior  cava,  must  consequently  pass 
from  the  right  auricle  into  the  right  ventricle  ami 
pulmonary  artery ; from  whence  a large  portion  of  it 
will  proceed  through  the  arterial  canal  into  the  aorta 
beyond  the  carotids  and  subclavians,  and  of  this  por- 
tion a considerable  part  will  go  to  the  placenta  by  the 
umbilical  atteries.  Sabatier  compares  the  course  of 
the  blood  in  the  foetus  to  the  course  of  afluidin  a tube 
which  has  the  form  of  the  numeral  character  8.* — If 
this  doctrine  be  true,  the  progress  of  the  blood  in  the 
foetus  and  placenta  is  very  analogous  to  that  of  the 
double  circulation  of  the  adult;  the  character  8 an- 
swering equally  well  in  the  description  of  either  sub- 
ject. 

According  to  Sabatier,  the  blood  of  the  placenta 
takes  this  peculiar  course  through  the  heart,  in  order 
that  some  of  it  may  be  carried  to  the  head  and  upper 
extremities.  But  an  additional  reason  may  be  sug- 
gested, which  appears  to  be  of  great  importance ; 
viz.  the  supplying  of  the  coroijary  or  proper  xesse\s 
of  the  heart  with  some  of  the  same  blood. 

The  heart  of  the  adult,  as  has  been  before  stated, 
cannot  act  without  its  proper  or  coronary  arteries  are 
supplied  with  arterial  blood.  The  heart  of  the  foetus 
performs  a more  extensive  circulation  than  that  of  the 
adult,  and  therefore  is  probably  in  greater  need  of 
such  blood.  But  unless  the  blood  of  the  placenta  pas- 
ses through  the  foramen  ovale  into  the  left  auricle  and 
ventricle , and  so  to  the  aorta , it  cannot  enter  the  coro- 
nary arteries  which  originate  at  the  commencement 
of  the  aorta;  for  the  b.lood  which  flows  from  the 
right  side  of  the  heart  through  the  arterial  canal, 
passes  into  the  aorta  at  so  great  a distance  from  the 
orifices  of  the  coronary  arteries,  that  it  certainly 
cannot  enter  them. 

The  whole  of  this  doctrine  seems  to  be  supported  by 
a fact,  very  familiar  to  accoucheurs,  viz.  the  occur- 
rence of  death  in  the  foetus  whenever  the  circulation 
through  the  umbilical  cord  issuspendedduringfifteen 
or  twenty  minutes:  for  as  the  placenta  imparts  to  the 
foetal  blood  a quality  essential  to  life,  some  arrange- 
ment seems  necessary  to  provide  for  the  equal  distri- 
bution of  the  blood  which  comes  from  this  organ,  and 

" See  Sabatier’3  Paper  on  this  subject  in  the  Memoirs  of  the  Academy 
of  Sciences,  for  3774. 


Unusual  Cases  of  Malformation . 77 

especially  for  carrying  the  requisite  proportion  of  it 
to  the  substance  of  the  heart. 


Life  has  existed  for  some  time  with  a structure  very 
different  indeed  from  that  which  is  natural.  In  the 
series  of  elegant  engravings  relating  to  morbid  ana- 
tomy, published  by  Dr.  Baillie,  is  the  representa- 
tion of  a heart,  in  which  the  venae  cavae  opened 
into  the  right  auricle,  aftd  the  pulmonary  veins  into 
the  left  auricle,  in  the  usual  manner  ; but  the  aorta 
arose  entirely  from  the  right  ventricle,  and  the  pul- 
monary artery  as  completely  from  the  left.  The 
canalis  arteriosus,  howevdr,  passed  from  the  pulmo- 
nary artery  to  the  aorta,  and  the  foramen  ovale  ex- 
isted. In  this  case  it  is  evident  that  the  pulmona- 
ry artery  must  have  carried  back  to  the  lungs  the 
arterial  blood  which  came  from  them  by  the  pulmo- 
nary veins,  with  a small  quantity  of  venous  blood 
that  passed  into  the  left  auricle  through  the  foramen 
ovale;  add  that  the  aorta  must  have  returned  to  the 
body,  the  venous  blood  which  just  before  had  been 
brought  from  it  by  the  venae  cavae,  with  a small  ad- 
dition of  arterial  blood  that  passed  through  the 
ductus  arteriosuss  Yet,  with  this  structure,  the 
child  Ijjved  two  months  after  its  birth, 

A case,  which  had  a strong  resemblance  to  the 
foregoing,  occurred  lately  in  Philadelphia,  and  was 
examined  by  the  author  of  this  work.  The  venae 
cavae  terminated  regularly  in  the  right  auricle,  and 
the  pulmonary  veins  in  the  same  regular  manner  in 
the  left ; but  the  pulmonary  artery  arose  from  the 
left  ventricle,  and  the  aorta  from  the  right.  There 
was  no  communication  between  these  vessels  by  a ca- 
nalis arteriosus  ; but  a large  opening  existed  in  the 
septum  between  the  auricles. 

It  is  very  evident,  that  in  this  case  also  the  pul- 
monary artery  must  have  returned  to  the  lungs  the 
arterial  blood  as  it  came  from  them,  and  the  aorta 
must  have  carried  back  to  the  general  system  the 
venous  blood  brought  to  the  heart  by  the  cavae  ; ex- 
cepting only  those  portions  of  the  arterial  and 
venous  blood  which  must  have  flowed  reciprocally 
from  one*auricle  into  the  other,  and  thus  changed 
their  respective  situations. 


78 


Foramen  Ovale . 


The  subject  was  about  two  years  and  a half  old. 
Tiie  heart  was  nearly  double  the  natural  size,  and 
the  foramen,  or  opening  in  the  septum  between  the 
auricles,  was  eight  or  nine  lines  in  diameter.  The 
pulmonary  artery  was  larger  in  proportion  than  the 
aorta  or  the  heart. 

With  this  organization  the  child  lived  to  the  age 
above  specified.  His  countenance  was  generally 
rather  livid  ; and  this  colour  was  always  much  in- 
creased by  the  least  irregularity  of  respiration.  His 
nails  were  alivays  livid.  He  sometimes  appeared 
placid,  but  more  frequently  in  distress.  He  never 
walked,  and  seldom,  if  ever,  stood  on  his  feet. 
When  sitting  on  the  floor,  he  would  sometimes  push 
himself  about  the  room;  but  this  muscular  exertion 
always  greatly  affected  his  respiration.  He  attain- 
ed  the  size  common  to  children  of  his  age,  and  had 
generally  a great  appetite.  For  some  weeks  before 
death  his  legs  and  feet  were  swelled. 

It  is  probable  that  the  protraction  of  life  depend- 
ed upon  the  mixture  of  the  blood  in  the  two  auri- 
cles ; and  that  they  really  were  to  be  considered  as 
one  cavity,  in  this  case. 

There  seems  reason  to  -believe,  thai^n  adults  of  the 
common  structure,  there  is  no  passage  of  blood  from 
one  auricle  to  the  other,  when  the  foramen  ovale 
has  remained  .open ; because  in  several  persons  in 
whom  it  was  found  by  dissection  to  have  remained 
open,  there  were  no  appearances  during  life  that  in- 
dicated the  presence  of  disoxygenated  blood  in  the 
aortic  system.  It  is  probable,  that  the  small  size 
of  the  foramen  ovale,  the  valvular  structure  which 
generally  exists  there,  and  the  complete  occupation 
of  the  left  auricle  by  the  blood  flowing  from  the  pul- 
monary veins,  prevent  the  passage  of  blood  from  the 
right  auricle  to  the  left,  in  such  persons  ; whereas, 
in  the  case  in  question,  the  opening  between  the 
auricles  was  very  large  indeed,  and  there  was  no 
appearance  of  a valve  about  it. 

Although  it  be  admitted,  that* in  adults  with  the 
foramen  ovale  pervious,  there  is  no  transmission  of 


On  the  Source  of  the  motion  of  the  Heart.  79 

blood  from  the  right  to  the  left  auricle  ; there  is 
every  reason  to  believe  that  this  transmission  goes 
on  steadily  in  the  fetus.  To  the  arguments, 
derived  from  the  structure  and  the  nature  of  the 
case,  it  may  be  added,  that  the  pulmonary  veins,  in 
the  fetal  state,  carry  to  the  left  auricle  a quantity 
of  blood,  not  sufficient  .to  fill  it;  while  the  venae 
cavse  carry  to  the  right  auricle  not  only  the  whole 
blood  of  the  body,  but  of  the  umbilical  cord  and 
placenta  : some  of  which  must  flow  into  the  unfilled 

• .left  auricle,  when  the  right  auricle  becomes  fully 

distended. 

The  question  how  far  the  functions  of  the  heart  and 
lungs  are  dependent  upon  the  brain  is  very  impor- 
tant, and  has  often  been  agitated  with  great  zeal. 
In  favour  of  the  opinion  that  the  motions  of  the 
heart  are  independent  of  the  brain,  may  be  stated 

• the  numerous  cases  in  which  the  brain  has  been  de- 
ficient in  children,  who  have  notwithstanding  lived 
the  full  period  of  utero-gestation,  and  even  a short 
time  after  birth,  and  have  arrived  at  their  full  size, 
with  every  appearance  of  perfect  vigour  and  action 
in  the  heart.  In  support  of  the  doctrine,  that  the 
action  of  the  heart  is  immediately  dependent  upon 
the  brain,  it  may  be  observed,  that  no  organ  of  the 
body  appears  to  be  so  much  influenced  by  passions 
and  other  mental  affections  as  the  heart.  These 
contradictory  facts  have  occasioned  this  question  to 
be  considered  as  undecided,  if  not  incapable  of  so- 
lution ; although  Cruikshank  and  Bichat*  have  stated 
circumstances  very  favourable  to  the  opinion  that 
the  motions  of  the  heart  are  independent  of  the 
brain. 

This  question  seems  now  to  be  settled  by  the  ex- 
periments of  Dr.  Legallois,  a physician  of  Paris, 

* See  Cruikshank’s  Experiments  on  the  Nerves  anc!  Spinal  Marrow  of 
living  animals  ; London  Philosophical  Transactions  for  1795.  The  eighth 
experiment  has  a particular  relation  to  this  subject. 

Bichat’s  researches,  part  2,  article  9. 

The  Abbe  Fontana  has  considered  this  subject  in  bis  Treatise  on  the 
Venom  of  the  Viper,  vol.  ii.  page  194,  English  translation  ■ and  also  in 
same  of  his  other  works. 


80  Humboldt  and  others  on  Legallois*  Paper . 

which  prove,  that  in  animals  who  have  suffered  de- 
capitation, the  action  of  the  heart  does  not  cease  as 
an  immediate  consequence  of  the  removal  of  the 
head  ; but  its  cessation  is  an  indirect  effect , induced 
by  the  suspension  of  respiration.  That  respiration 
is  immediately  affected  by  decapitation,  and  depends 
upon  the  influence.of  the  brain  transmitted  through 
the  eighth  pair  of  nerves.  That  the  action  of  the 
heart  will  continue  a long  time  after  decapitation, 
* if  inflation  of  the  lungs,  or  artificial  respiration,  be 
performed  ; but,  on  the  contrary,  if  the  spinal  mar - 
' row  be  destroyed,  the  action  of  the  heart  ceases  ir- 
recoverably. 

The  inference  from  these  experiments  seems  very 
conclusive,  that  the  Spinal  Marrow , and  not  the 
brain,  is  the  source  of  the  motions  of  the  heart. 

It  appears  also  by  some  of  the  experiments,  that 
the  power  of  motion  in  the  trunk  of  the  body  is  de- 
rived from  the  spinal  marrow;  and  that  when  this  or- 
gan is  partially  destroyed,  the  parts  which  receive 
nerves  from  the  destroyed  portion  soon  cease  to  live. 
By  particular  management  of  the  spinal  marrow, 
one  part  of  the  body  can  be  preserved  alive  for 
some  time  after  the  other  parts  are  dead. 

These  experiments  of  Dr.  Legallois  commenced  in 
1806  or  1807,  and  were  communicated  to  the  Im- 
perial Institute  of  France  in  1811.  The  committee 
of  that  body  to  whom  they  were  referred,  viz. 
Messrs.  Humboldt,  Halle  and  Percy,  reported  that 
the  experiments  had  been  repeated  before  them,  at 
threfe  different  meetings  of  several  hours  each  ; and 
that'  to  allow  themselves  sufficient  time  for  reflec- 
tion, they  suffered  an  interval  of  a week  to  take 
place  between  the  meetings.  The  committee  be- 
lieve these  experiments  to  have  proved, 

1st.  That  the  principle  upon  which  all  the  move- 
ments of  inspiration  depend,  has  its  seat  about  that 
part  of  the  medulla  obiongatafrom  which  the  nerves 
of.  the  eighth  pair  arise. 

2d.  That  the  principle  which  animates  each  part  of 
the  trunk  of  the  body  is  seated  in  that  portion  of  the 
spinal  marrow  from  which  the  nerves  of  the  part  arise. 

3.  That  the  source  of  the  life  and  strength  of 
the  heart  is  also  in  the  spinal  marrow;  not  in  any 
distinct  portion,  but  in  the  whole  of  it. 


Brodie  on  the  Source  of  the  Motion  of  the  Heart . 81 

4th.  That  the  great  sympathetic  nerve  is  to  be  consi- 
dered as  originating  in  the  spinal  marrow,  and  that  the 
particular  character  of  this  nerve  is  to  place  each  of 
the  parts  to  which  it  is  distributed  under  the  immedi- 
ate influence  of  the  whole  nervous  power. 

The  interesting  memoir  of  Dr.  Legal lois  is  confirmed  to 
a certain  degree  by  a communication  of  B.  C.  Brodie 
to  the  Royal  Society  of  London  in  1810,  in  which  are 
detailed  many  very  interesting  experiments  which  in- 
duced the  author  to  conclude, — 

That  the  influence’  of  the  brain  is  not  directly  ne- 
cessary to  the  action  of  the  heart ; and 

That  when  the  brain  is  injured  or  removed,  the  action 
of  the  heart  ceases,  only  because  respiration  is  under  its 
influence ; and  if  under  these  circumstances  respira- 
tion is  artificially  produced,  the  circulation  will  still 
continue. 

These  various  experiments  apply  particularly  to  the  cases 
in  which  the  brain  is  deficient.  The  effects  of  mental 
agitations  on  the  heart  are  likewise  reconcilable  to  the 
theory  which  arises  out  of  them.  But  they  throw  no 
light  on  the  question  why  the  motions  of  the  heart  are 
so  perfectly  free  from  the  influence  of  the  will : and 
although  they  seem  to  prove  incontestibly  that  the  mo- 
tion of  the  heart  is  independent  of  the  brain,  it  ought 
to  be  remembered  that  in  certain  diseased  states  of 
the  brain,  where  that  organ  appears  to  be  compressed, 
the  action  of  the  heart- is  often  very  irregular,  and  its 
contractions  less  frequent  than  usual. 


VOL.  II. 


11 


SYSTEM  OF  AX  ATOMY. 

PART  VIII. 


OF  THE  ABDOMEN. 

The  lowermost  of  the  two  great  cavities  of  the 
trunk  of  the  body  is  called  Abdomen.  The  pelvis 
may  be  considered  as  a chamber  of  this  cavity,  al- 
though its  structure  is  very  different. 

CHAPTER  I. 

A GENERAL  VIEW  OF  THE  ABDOMEN  AND  PELVIS  AND 

THEIR  CONTENTS,  WITH  AN  ACCOUNT  OF  THE  PE- 
RITONEUM. 

, SECTION  I. 

Of  the  Abdomen. 

This  great  cavity  occupies  more  than  half  of  the 
space  enclosed  by  the  ribs,  and  all  the  interior  of  the 
trunk  of  the  body  below  the  thorax. 

It  is  formed  by  the  diaphragm,  supported  by  the 
lower  ribs ; by  a portion  of  the  spine  ; by  the  vari- 
ous muscles  which  occur  between  the  lower  margin 
of  the  thorax  and  the  upper  margin  of  the  ossa  in- 
nominata ; and  by  the  ossa  innominata,  which  con- 
tribute, for  the  purpose,  the  costas  of  the  ossa  ilia, 
as  well  as  the  pelvis. 


S3 


Construction  of  the  Abdomen. 

The  general  figure  of  this  cavity  partakes  of  the 
figure  of  the  lower  part  of  the  trunk  of  the  body  ; 
with  these  exceptions,  that  the  diaphragm  makes  it 
arched  or  vaulted  above,  that  the  spine  and  psose 
muscles,  &e.  are  rather  prominent  on  the  posterior 
surface,  and  that  the  lower  part  corresponds  with  the 
costas  of  the  ossa  ilia  and  with  the  pelvis. 

To  acquire  a precise  idea  of  this  cavity,  it  is  ne- 
cessary first  to  study  the  bones  concerned  in  its 
structure,  in  their  natural  situation  in  the  skeleton ; 
and  then  the  muscles,  which  form  so  large  a part 
of  it. 

The  arrangement  of  the  tendons  of  some  of  these 
muscles,  with  a view  to  complete  the  cavity,  is  par- 
ticularly interesting  ; as  that  of  the  external  oblique 
where  it  forms  the  crural  arch.*  The  ligaments  of 
the  pelvis  and  the  levatores  ani  muscles,  as  they  also 
contribute  to  the  formation  of  the  cavity,  and  have 
an  influence  upon  its  figure,  should  likewise  be  at- 
tended to. 

In  the  walls  of  the  cavity,  thus  constructed,  there 
are  many  foramina  by  which  the  viscera  and  other 
contained  parts  communicate  externally  ; but  few  of 
them  pass  directly  into  the  cavity  ; for  like  the  tho- 
rax, there  are  no  vacuities  in-  it  exterior  to  the  con- 
tained organs. 

Three  of  these  foramina  are  in  the  diaphragm. 
One  for  the  transmission  of  the  aorta,  another  for  the 
vena  cava,  and  a third  for  the  oesophagus.  Below, 
there  is  an  aperture  at  each  of  the  crural  arches,  for 
the  transmission  of  the  great  femoral  vessels  ; in  each 
of  the  ligamentous  membranes,  which  close  the  fora- 
men thyroideum,  for  the  obturator  vessels  and  nerve; 
and  at  the  sacro  sciatic  notches,  for  nerves  and  blood 
vessels. 

* See  the  account  of  this  tendon,  vol.  i.  in  the  description  of  the  “ Ob* 
liquus  Decendens  Externus.” 


84 


Construction  of  the  Abdomen, 

There  are  also  two  apertures  at  the  bottom  of  the 
pelvis,  for  the  orifice  of  the  rectum  and  of  the  ure- 
thra. In  the  tendons  of  the  external  oblique  mus- 
cles are  two  orifices,  covered  by  the  integuments,  for 
the  spermatic  cords  ; and,  in  the  foetal  state,  one  for 
the  umbilical  cord. 

The  apertures  in  the  tendons,  and  under  their 
edges,  for  the  transmission  of  the  spermatic  cords, 
and  the  blood  vessels,  &c.  are  not  to  be  considered 
as  simple  perforations  made  abruptly;  but  the  edges 
of  these  foramina  are  formed  by  tendinous  mem- 
branes turned  inwards  and  continued  so  as  to  com- 
pose a cylindrical  tube,  which  becomes  gradually  so 
thin  that  it  cannot  be  readily  distinguished  from  the 
cellular  membrane  with  which  it  is  connected.*  The 
blood  vessels,  &c.  pass  along  this  tube  before  they  go 
through  the  apertures. 

It  is  evident  from  the  construction  of  this  cavity 
that  it  is  essentially  different  from  the  thorax.  It 
has  no  power  of  spontaneous  dilatation  whatever  : it 
yields  passively  to  the  distention  of  the  stomach  and 
intestines,  during  deglutition,  and  when  air  is  extri- 
cated from  the  aliment,  &c.  ; but  it  is  particularly 
calculated  for  compressing  its  contents  by  the  con- 
traction of  the  muscles*  which  compose  it.  The  di- 
minution of  its  capacity,  which  is  thus  effected,  not 
only  takes  place  to  a great  degree,  but  occasionally 
with  great  force.  The  diaphragm  and  the  abdomi- 
nal muscles  may  be  considered  in  some  measure  as 
antagonists  of  each  other.  When  the  diaphragm 
descends,  if  the  abdominal  muscles  are  passive,  they 
are  distended  by  the  contents  of  the  abdomen,  which 
are  forcibly  pressed  from  above  ; but  if  the  abdomi- 
nal muscles  act  at  the  same  time,  an  effort  to  dimi- 

* The  [student  of  anatomy,  ■when  engaged  with  this  subject,  will  be 
gratified  by  the  examination  of  Mr.  Astley  Cooper’s  plates  relating  to 
hernias. 


Contents  of  the  Abdomen.  85 

msh  the  cavity  in  every  direction  takes  place,  and  the 
contained  parts  are  compressed  with  more  or  less  force 
according  to  the  exertion  made.  This  will  be  very 
evident  upon  examining  the  situation  of  the  diaphragm 
and  of  the  abdominal  muscles.  When  their  force  is 
considered  it  will  also  be  very  obvious  that  the  vari- 
ous outlets  of  the  cavity  are  constructed  most  advan- 
tageously ; otherwise  hernia  or  protrusion  of  its  con- 
tents would  be  a daily  occurrence. 

The  abdomen  contains,  1st.  The  Stomach  and  the 
whole  Intestinal  Tube,  consisting  of  the  small  and 
the  great  intestines. 

2d.  The  Assisting  Ckylopoietic  Viscera, — the 
Liver,  the  Pancreas  and  the  Spleen. 

3d.  The  Urinary  Organs , — the  Kidneys,  the 
Ureters,  and  the  Bladder.  To  which  should  be  add- 
ed the  Glandulae  Renal es. 

4.  The  Organs  of  Generation  in  part:  those  of 
the  female  sex  being  almost  wholly  included  in  the 
pelvis ; and  those  of  the  male  being  situated  partly 
within  and  partly  without  it. 

5th.  The  Peritoneum  and  its  various  processes. 
The  Mesentery,  Omentum,  &c. 

6th.  A portion  of  the  Aorta,  and  almost  the 
whole  of  the  Inferior  Cava,  and  their  great  ramifi- 
cations ; with  such  of' their  branches  as  are  appro- 
priated to  the  Viscera  of  the  Abdomen  and  Pelvis. 

7th.  Those  portions  of  the  Par  Vagum  and  In- 
tercostal Nerves  which  are  appropriated  to  the  cavi- 
ty ; and  portions  of  some  of  the  nerves  destined  to 
the  lower  extremities. 

. 8th.  The  lower  part  of  the  Thoracic  Duct,  or 
the  Great  Trunk  of  the  Absorbent  System,  with  the 
large  branches  that  compose  it,  and  the  glands  con- 
nected with  them  ; and  also  those  absorbent  vessels 
called  Lacteals,  and  their  glands. 

As  the  cavity  of  the  abdomen  has  no  natural  divi- 


86  Regions  of  the  Abdomen . 

sions,  anatomists  have  divided  it  by  imaginary  lines 
into  various  regions,  with  a view  to  precision  in  their 
accounts  of  the  situation  of  the  different  contained 
parts.  Thus, 

They  have,  very  generally,  agreed  to  apply  two 
transverse  lines  to  form  three  great  divisions ; viz. 
the  Upper , Middle,  and  Lower : and  they  have  also 
agreed  that  each  of  these  divisions  shall  be  subdivid- 
ed into  three  regions. 

The  three  regions  of  the  uppermost  division  are 
defined  with  some  precision.  Those  on  each  side, 
which  are  called  the  Right  and  Left  Hypochondriac 
regions,  occupy  the  spaces  immediately  within  the 
lower  ribs  and  their  cartilages ; while  the  middle 
space,  included  within  the  margins  of  these  cartila- 
ges, and  a line  drawn  from  the  lower  edge  of  the 
thorax  on  one  side  to  that  on  the  other,  is  denomi- 
nated the  Epigastric  region. 

The  boundaries  of  the  regions  below  are  less  pre- 
cisely defined. 

Many  anatomists  have  fixed  the  two  transverse 
lines  above  mentioned  at  an  arbitray  distance  above 
and  below  the  umbilicus  : some  choosing  for  this  pur- 
pose two  inches,  and  others  a hand’s  breadth.  As 
these  distances  will  occupy  different  proportions  of 
the  cavity  in  persons  of  different  stature,  other  ana- 
tomists, with  a view  to  avoid  this  inconvenience,  have 
proposed  to  connect  these  lines  With  certain  fixed 
points  of  the  skeleton. 

It  is  of  importance  that  the  boundaries  of  these 
regions  should  be  fixed,  and  therefore  the  proposi- 
tion of  Sabatier  may  be  adopted  ; viz.  To  draw  the 
upper  transverse  line  from  the  most  inferior  part  of 
the  lower  margin  of  the  thorax,  on  one  side,  to  the 
corresponding  part  on  the  opposite  side ; and  the 
lower  transverse  line  from  the  uppermost  part  of  the 


87 


Regions  of  the  Abdomen. 

spine  of  one  ilium  to  the  same  part  of  the  other. 
These  lines  will  mark  the  three  great  divisions.  If 
then  two  parallel  lines  are  drawn  directly  upwards, 
one  from  each  of  the  superior  anterior  spinous  pro- 
cesses of  the  ilium  until  it  touches  the  lower  margin 
of  the  thorax,  they  will  divide  each  of  the  two  lower 
divisions  of  the  abdomen  into  three  regions.  The 
centre  of  the  middle  division  is  the  umbilical,  and 
on  each  side  of  it  is  the  right  and  left  lumbar  region. 
The  middle  of  the  lower  division  is  the  hypogastric  ; 
and  on  each  side  of  it  the  right  and  left  iliac  region. 

It  is  true,  that  the  three  middle  regions  of  the  ab- 
domen will  be  made  very  small  by  the  vicinity  of  the 
transverse  lines  to  each  other ; but  the  advantages 
derived  from  a principle  which  is  similar  in  its  ap- 
plication to  all  subjects  fully  compensates  for  this  in- 
convenience. 

There  are  therefore  nine  of  these  regions : viz. 
The  Epigastric  and  the  two  Hypochondriac:  the  Um- 
bilical, and  the  two  Lumbar : the  Hypogastric,  and 
the  two  Iliac  regions.*  And  it  should  be  added, 
that  the  space  immediately  around  the  end  of  the  ster- 
num is  sometimes  called  the  Scrobiculus  Cordis ; 
and  the  space  immediately  within  the  os  pubis,  the 
Regio  Pubis. 

These  different  regions  are  generally  occupied  in 
the  following  manner.  The  liver  fills  nearly  the 
whole  of  the  right  hypochopdriac  region,  and  ex- 
tends through  the  upper  part  of  the  epigastric  region 
into  the  left  hypochondriac.  The  stomach  occupies 
the  principal  part  of  the  epigastric  region,  and  a 
considerable  portion  of  the  left  hypochondriac.  The 
spleen  is  also  situated  in  the  left  hypochondriac  re- 


* It  is  to  be  observed  that  the  lateral  regions  of  the  middle  and  lower  di- 
visions of  the  abdomen  are  named  differently  bv  different  writers. 


38 


Situation  of  the  Viscera,  6,'C.  in  the 

gion.  That  portion  of  the  intestinal  tube,  which  is 
composed  of  small  intestines,  is  generally  found  in 
the  umbilical,  the  hypogastric,  and  the  iliac  regions ; 
and  when  the  bladder  is  empty,  in  the  pelvis.  But 
the  duodenum,  or  first  of  the  small  intestines,  which 
proceeds  immediately  from  the  stomach,  is  situated 
in  the  epigastric  and  umbilical  regions.  The  great 
intestine  commences  in  or  near  the  right, iliac  region, 
and  ascends  through  the  right  lumbar*  to  the  right 
hypochondriac  region.  It  then  crosses  the  abdomen, 
passing  through  the  lower  part  of  the  epigastric,  01s 
upper  part  of  the  umbilical  to  the  left  lumbar  region  ; 
from  this  it  continues  into  the  left  iliac  region,  and 
curves  in  such  a manner  that  it  finally  arrives  at  the 
middle  of  the  upper  part  of  the  os  sacrum,  when  it 
descends  into  the  pelvis,  and,  partaking  of  the  cur- 
vature of  the  last  mentioned  bone,  continues  to  the 
termination  of  the  os  coccygis. 

In  the  back  part  of  the  epigastric  region,  and  very 
low  down  in  it,  is  situated  the  pancreas.  The  kid- 
neys lie  in  the  most  posterior  parts  of  the  lumbar  re- 
gions, and  from  each  of  them  is  continued  a tube  or 
duct,  called  Ureter,  that  passes  into  the  pelvis  to  con- 
vey the  urine  to  the  bladder.  This  viscus,  in  males, 
is  in  contact  with  the  last  portion  of  the  great  intes- 
tine called  the  Rectum,  and  with  it  occupies  almost 
all  the  cavity  of  the  pelvis  ; while  in  females,  the 
uterus  and  its  appendages  are  situated  between  this 
intestine  and  the  bladder. 

In  the  posterior  part  of  the  abdomen,  in  contact 
with  the  spine  is  the  aorta.  This  great  blood  ves- 
sel passes  from  the  thorax  between  the  crura  of  the 
diaphragm,  and  continues  down  the  spine  until  it 
approaches  towards  the  pelvis,  when  it  divides  into 
two  great  branches  called  the  Iliac  Arteries.  Each 
of  these  great  branches  divides  again,  on  the  side 


89 


Cavity  of  the  Abdomen. 

of  the  pelvis,  into  two ; viz.  the  External  Iliac , 
which  passes  under  the  crural  arch  to  the  thigh,  and 
the  Internal  Iliac,  or  Hypogastric , which  descends 
into  the  cavity  of  the  pelvis. 

Soon  after  the  arrival  of  the  aorta  in  the  abdomen 
it  gives  off  two  large  branches.  The  first,  which  is 
called  the  Cceliac,  is  distributed  to  the  liver,  the  sto- 
mach, and  the  spleen : the  second,  called  the  Supe- 
rior Mesenteric,  is  spent  upon  the  intestines.  Lower 
down,  in  the  abdomen,  it  also  sends  off  a small 
branch  for  the  intestines,  called  Inferior  Mesen- 
teric. Besides  these  vessels  for  the  chylopoietic  vis- 
cera, the  aorta  sends  off  a large  branch,  called  Emul- 
gent,  to  each  kidney. 

The  inferior  or  ascending  vena  cava  is  situated 
on  the  right  of  the  aorta,  in  front  of  the  spine.  It  is 
formed  below  by  the  union  of  the  iliac  veins,  and  in 
its  progress  upwards  it  receives  the  emulgent  veins, 
which  correspond  to  the  arteries  of  the  kidneys ; but 
it  receives  in  its  course  no  veins  which  correspond 
directly  with  the  cceliac  and  mesenteric  arteries. 
The  smaller  veins,  that  answer  to  the  branches  of 
these  arteries,  unite  and  form  one  large  vein,  which 
goes  to  the  liver,  and  is  called,  (from  the  part  of  that 
viscus  at  which  it  enters,)  Vena  Portarum.  From 
the  liver  three  large  veins  pass  into  the  vena  cava, 
and  deposit  there  the  blood  of  the  vena  portarum, 
after  it  has  furnished  materials  for  the  secretion  of 
bile.  The  vena  cava,  in  its  passage  upwards,  is  in 
close  contact  with  the  posterior  .thick  edge  of  the 
liver  : it  often  passes  along  a deep  groove  in  this 
edge,  and  sometimes  it  is  completely  surrounded  by 
the  liver  in  its  course.  The  veins  of  the  liver  enter 
the  vena  cava  at  this  place,  and  of  course  they  are 
not  to  be  seen  without  dissection.  Immediately  af- 
ter leaving  the  liver  the  vena  cava  passes  through  an 

Vol.  ii.  12 


90 


The  Peritoneum. 


aperture  in  the  tendinous  centre  of  the  diaphragm 
to  unite  itself  to  the  right  auricle  of  the  heart. 

SECTION  II. 

Of  the  Peritoneum. 

The  abdomen,  thus  constructed  and  occupied,  is 
lined  by  a thin  firm  membrane  called  Peritoneum , 
which  is  extremely  smooth  on  its  internal  surface, 
and  is  immediately  connected  with  the  cellular  sub- 
stance exterior  to  it.  This  membrane  adheres  close- 
ly to  the  anterior,  lateral,  and  superior  portions  of  the 
surface  of  the  abdomen ; and  is  extended  from  the 
posterior  surface  so  as  to  cover,  more  or  less  com- 
pletely, the  viscera  of  the  cavity.  Those  viscera 
which  are  in  close  contact  with  the  posterior  surface 
of  the  abdomen,  as  some  portions  of  the  large  intes- 
tine, are  covered  only  on  their  anterior  surfaces,  and 
are  fixed  in  their  precise  situation  by  the  peritone- 
um ; which  extends  from  them  to  the  contiguous 
surface  of  the  cavity,  and  adheres  where  it  is  in  con- 
tact, so  as  to  produce  this  effect. 

Other  viscera,  which  are  not  in  close  contact,  but 
moveable  to  a distance  from  the  posterior  surface  of 
the  abdomen,  are  covered  by  this  membrane,  which 
is  extended  to  them  from  the  surface ; and  this  ex- 
tended portion  forms  an  important  part  of  the  con- 
nexion between  the  viscus  and  the  cavity  in  which  it 
lies.  This  connecting  part  is  called  Mesentery , 
when  it  thus  passes  to  the  small  intestines;  Mesoco- 
lon.,  when  it  goes  to  the  colon,  one  of  the  larger  in- 
testines ; and  Ligoment , when  it  passes  to  some  of 
the  other  viscera. 

The  peritoneum  is  a complete  but  empty  sac, 
which  is  fixed  in  the  abdomen  anterior  to  the  viscera. 
The  anterior  portion  of  this  sac  forms  the  lining  to 
the  anterior  and  lateral  parts  of  the  surface  of  the 


The  Peritoneum. 


91 


abdomen : the  posterior  portion  covers  the  viscera,, 
and  forms  the  mesentery,  mesocolon,  and  ligaments 
above  described.  * 

It  necessarily  follows  that  the  mesentery  and  the 
other  similar  processes  are  mere  plaits  or  folds  of  the 
sac,  which  invests  the  viscera  ; and  that  they  must 
consist  of  two  lamina ; and  as  the  blood  vessels, 
nerves,  and  absorbents,  are  all  posterior  to  the  peri- 
toneum, they  naturally  pass  between  these  lamina  of 
the  mesentery. 

Some  of  the  viscera  are  much  more  completely  in- 
vested with  the  peritoneum  than  others.  The  sto- 
mach, liver,  and  spleen,  are  almost  completely 
surrounded  by  it ; and  it  is  said  to  form  a coat  for 
each  of  these  viscera.  That  portion  of  the  smaller 
intestinal  tube,  which  is  called  jejunum  and  ileum, 
and  the  transverse  portion  of  the  large  intestine,  call- 
ed the  arch  of  the  colon,  are  invested  by  it  in  the 
same  way.  But  a considerable  portion  of  the  duo- 
denum and  the  pancreas  is  behind  it.  The  lateral 
portions  of  the  colon  are  in  close  contact  with  the 
posterior  surface  of  the  abdomen,  and  the  peritone- 
um only  covers  that  portion  of  their  surfaces  which 
looks  anteriorly  towards  the  cavity  of  the  abdomen, 
and  is  not  in  contact  with  its  posterior  surface. 

The  urinary  organs  are  not  much  connected  with 
the  peritoneum.  The  kidneys  appear  exterior  to  it, 
and  behind  it:  the  bladder  of  urine  is  below  it,  and 
has  but  a partial  covering  from  it,  on  its  upper  por- 
tion. 

The  peritoneum,  which  covers  the  stomach,  is  ex- 
tended from  the  great  curvature  of  that  organ  so  as 
to  form  a large  membrane,  which  descends  like  an 
apron  before  the  intestines.  This  process  of  perito- 
neum is  composed  of  two  lamina,  so  thin  and  deli- 
cate as  to  resemble  cellular  membrane,  which,  after 
extending  downwards  to  the  lower  part  of  the  abdo- 


92 


The  Peritoneum. 


men,  are  turned  backwards  and  upwards,  and  pro- 
ceed  in  that  direction  until  they  arrive  at  the  colon, 
which  they  enclose,  and  then  continue  to  the  back  of 
the  abdomen,  forming  the  mesocolon.  The  part  of 
this  process  which  is  between  the  stomach  and  the 
colon,  is  called  Epiploon  or  Omentum. 

This  extension  of  a membrane,  from  the  surface 
of  a cavity,  which  it  lines  to  the  external  surface  of 
a viscus  in  that  cavity,  is  called,  by  some  anatomists, 
“ reflection  and  the  technical  term  reflected  mem- 
brane is  therefore  applied  to  a membrane  distributed 
like  the  peritoneum. 

It  must  be  evident  that  this  distribution  of  the  pe- 
ritoneum is  very  complex,  and  that*  it  is  not  easy  to 
form  an  accurate  conception  of  it  from  description, 
but  it  can  be  readily  understood  by  demonstration  ; 
therefore  no  further  account  of  its  arrangement  will 
now  be  attempted,  but  each  of  its  processes  will  be 
considered  with  the  organs  to  which  they  are  parti- 
cularly subservient. 

That  portion  of  the  peritoneum  which  lines  the 
abdomen  and  covers  the  viscera,  is  thin  and  delicate, 
but  very  firm.  It  yields  to  distension,  as  in  preg- 
nancy, ascites,  &c.  and  again  recovers  its  dimen- 
sions. It  was  formerly  thought  to  be  composed  of  two 
lamina,  but  this  cannot  be  proved.  The  internal 
surface  of  this  membrane  is  very  smooth,  and  highly 
polished  ; and  from  it  exudes  a liquor  which  is  well 
calculated  for  lubrication,  and  barely  sufficient  to 
keep  the  surface  moist  during  health  ; but  sometimes 
it  is  very  abundant,  and  occasions  the  aforesaid  dis- 
ease— ascites.  This  fluid  appears  to  exude  from 

the  surface  of  the  peritoneum  when  it  is  compressed 
in  a living  animal,  or  in  one  recently  dead.  It  is 
probably  efl'used  from  the  extremities  of  arteries,  for 
an  effusion  takes  place  when  water  is  injected  into 
these  vessels. 


The  Peritoneum . 


93 


The  peritoneum  abounds  with  absorbent  vessels, 
and  therefore  possesses  the  power  of  absorption  to  a 
great  degree.  This  power  may  be  inferred,  not  only 
from  the  spontaneous  removal  of  the  fluid  of  ascites, 
but  if  milk  and  water  be  introduced  into  the  abdomen 
of  a living  animal,  through  a puncture,  it  will  also 
disappear. 

The  blood  vessels  of  the  peritoneum  are  derived 
from  those  which  supply  the  neighbouring  parts. 
Nerves  have  not  yet  been  traced  into  it,  and  it  has 
little  or  no  sensibility. 

This  membrane  supports  the  viscera  of  the  abdo- 
men in  their  proper  situations  ; and  also  forms  a sur- 
face for  them,  and  for  the  cavities  which  contains 
them,  so  smooth  and  lubricated,  that  no  injury  can 
arise  from  their  friction. 

The  cellular  substance,  by  which  the  peritoneum 
is  connected  to  the  contiguous  parts,  is  very  different 
in  different  places.  It  is  very  short  indeed  between 
this  membrane  and  the  stomach  and  intestines,  and 
also  between  it  and  the  tendinous  centre  of  the  dia- 
phragm. Between  the  peritoneum  and  the  muscles 
generally,  it  is  much  longer.  When  it  covers  the 
kidneys  and  the  psoas  muscles  it  is  very  lax  and 
yielding.  About  the  kidneys  a large  quantity  of 
adeps  very  commonly  collects  in  it.  On  the  psoas 
muscle  it  yields  with  but  little  resistance  to  the  pas- 
sage of  pus,  or  any  other  effused  fluid,  as  in  the  case 
of  the  psoas  abscess. 


CHAPTER  II. 


OF  THE  OESOPHAGUS,  THE  STOMACH,  AND  THE  IN- 
TESTINES. 

SECTION  I. 

Of  the  (Esophagus . 

The  (Esophagus  is  a muscular  tube  which  passes 
from  the  pharynx  to  the  stomach,  and  is  so  intimate- 
ly connected  with  the  stomach,  that  it  will  be  advan- 
tageous to  the  student  to  attend  to  its  structure  im- 
mediately before  he  engages  in  the  examination  of 
that  important  organ. 

The  pharynx  has  been  lately  described*  as  com- 
posed of  a varied  stratum  of  muscular  fibres,  lined  by 
a membrane  which  is  continued  from  the  internal  sur- 
face of  the  nose  and  mouth.  From  the  pharynx  the 
oesophagus  passes  downwards  between  the  trachea 
and  the  vertebrae.  After  the  bifurcation  of  the  tra- 
chea, it  proceeds  in  contact  with  the  spine,  between 
the  lamina  of  the  mediastinum,  to  the  diaphragm, 
which  it  passes  through,  and  then  terminates  in  the 
stomach. 

The  oesophagus  is  a flexible  tube,  which,  when 
distended,  is  nearly  cylindrical.  It  consists  of  a 
muscular  coat  externally,  and  an  internal  tunic  evi- 
dently continued  from  that  of  the  pharynx.  These 
coats  are  connected  by  a cellular  substance  called 
the  Nervous  Coat , which  is  remarkably  loose,  and 
allows  them  to  move  considerably  upon  each  other. 
The  muscular  coat  which  is  very  distinguishable 
from  that  of  the  pharynx,  consists  of  two  substantial 
strata  of  fibres ; the  exterior  of  which  is  nearly  lon- 


* See  page  37. 


The  (Esophagus.  95 

• 

gitudinal  in  its  direction,  and  the  interior  circular  or 
transverse. 

The  internal  coat  of  the  oesophagus,  resembling 
that  of  the  fauces,  is  soft  and  spongy.  It  is  covered 
with  a very  delicate  cuticle,  which  Haller  supposed 
to  be  to  tender  to  confine  the  matter  of  variolous 
pustules,  as  he  had  never  found  these  extending  into 
the  oesophagus.  It  is  very  vascular,  and  abounds 
with  the  orifices  of  mucous  follicles,  from  which  is 
constantly  poured  out  the  mucous  that  is  spread  over 
this  surface.  When  the  oesophagus  is  not  distended, 
many  longitudinal  plaits  are  found  in  this  membrane 
by  the  contraction  of  the  circular  or  transverse  fibres 
exterior  to  it.  These  plaits  are  calculated  to  admit 
readily  of  the  distention  which  is  requisite  in  deglu- 
tition. This  tunic  is  continued  from  the  lining  mem- 
brane of  the  pharynx  above,  and  terminates  below  in 
the  villous  coat  of  the  stomach  ; from  which,  howev- 
er, it  is  very  different. 

The  blood  vessels  of  the  oesophagus  come  from 
those  which  are  in  the  vacinity.  The  nerves  are 
derived  from  the  eighth  pair.  The  lymphatic  ves- 
sels are  very  abundant. 

In  the  neck,  the  oesophagus  inclines  rather  to  the 
left  of  the  middle  line.  As  it  proceeds  down  the 
back  between  the  lamina  of  the  mediastinum,  it  pre- 
serves the  same  course  to  the  fourth  dorsal  vertebra, 
when  it  assumes  the  middle  portion  and  proceeds 
downwards,  with  the  aorta  to  its  left,  and  the  peri- 
cardium before  it.  About  the  ninth  dorsal  vertebra 
it  inclines  again  rather  to  the  left,  and  somewhat  for- 
ward, to  arrive  at  the  aperture  in  the  diaphragm 
through  which  it  passes. 

Throughout  this  course  it  is  connected  by  cellular 
membrane  to  the  contiguous  parts  ; and  this  investi- 
ture of  cellular  membrane  has  been  called  its  Ex- 
ternal Coat, 


96 


Form  of  the  Stomach. 

While  the  oesophagus  is  in  the  posterior  mediasti- 
num, it  is  in  contact  with  several  small  absorbent 
glands,  especially  when  it  first  assumes  a situation 
to  the  right  of  the  aorta.  These  glands  were  for- 
merly believed  to  be  particularly  connected  with 
this  tube,  but  they  are  now  considered  as  belonging 
to  the  absorbent  system.  They  are  sometimes  great- 
ly  enlarged. 

SECTION  II. 

Of  the  Stomach. 

This  most  important  organ  which  occasionally 
exerts  a powerful  influence  upon  every  part  of  the 
body,  appears  very  simple  in  its  structure. 

It  is  a large  sac,  which  is  so  thin  when  much  in- 
flated that  at  first  view  it  seems  membranous,  but 
upon  examination  is  found  to  be  composed  of  several 
lamina  or  coats,  each  of  a different  structure.  It  is 
of  considerable  length,  but  incurvated.  It  is  much 
larger  at  one  extremity  than  the  other,  and  changes 
so  gradually  in  this  respect,  that  it  would  appear 
conical  if  it  were  straight.  It  is  not,  however,  strictly 
conical,  unless  it  is  greatly  distended  ; for  when 
moderately  distended,  a transverse  section  is  rather 
oval  than  circular.  It  is  therefore  considered  as  hav- 
ing two  broad  sides  or  surfaces,  and  two  edges, 
which  are  the  curvatures.  It  has  been  compared  by 
the  anatomists  of  different  nations  to  the  wind  sac 
of  the  musical  instrument  called  the  bagpipe.*  The 
orifice  in  which  the  oesophagus  terminates  is  at  a 
small  distance  from  its  largest  extremity,  and  is 
called  Cardia.  The  orifice  which  communicates 

* The  student  ought  not  to  attempt  to  acquire  an  idea  of  the  form  of 
the  stomach  without  demonstration,  for  a view  of  one  moment  will  be 
more  serviceable  than  a long  description. 


Position  of  the  Stomach . 97 

with  the  intestines  is  at  the  termination  of  its  small 
incurvated  extremity,  and  is  called  the  Pylorus, 

The  two  ends  of  the  stomach  being  thus  very  dif- 
ferent in  size,  are  denominated  the  great  and  small 
extremities.  The  two  curved  portions  of  the  surface 
are  also  called  the  great  and  small  curvatures.  The 
two  flat  portions  of  the  surface,  or  the  broadsides, 
are  called  the  anterior  and  posterior  surfaces. 

The  situation  of  the  stomach  in  the  abdomen  is 
nearly  transverse  : it  lies  principally  in  the  left  hy- 
pochondriac and  epigastric  regions,  immediately  be- 
low the  liver.  The  great  extremity  of  the  stomach 
is  in  the  left  hypochondriac  region,  and  the  lesser 
extremity  in  the  epigastric  region,  under  the  left 
lobe  of  the  liver.  The  upper  orifice,  or  Cardia,  is 
nearly  opposite  to  the  body  of  the  last  dorsal  ver- 
tebra ; and  owing  to  the  curved  form  of  the  stomach, 
the  other  orifice,  or  Pylorus , is  situated  at  a small 
distance  to  the  right  of  that  bone,  and  rather  lower 
and  more  forward  than  the  cardia  ■:  both  orifices  be- 
ing in  the  epigastric  region.  The  position  of  the 
stomach  is  oblique  in  two  respects  ; it  inclines  in  a 
small  degree  from  above  downwards,  from  the  left 
to  the  right ; and  it  also  inclines  downwards  and 
forwards,  from  behind.  Its  two  orifices  are  situated 
obliquely  with  respect  to  each  other ; for,  if  the  sto- 
mach, when  placed  with  its  small  curvature  upwards, 
were  divided  into  two  equal  parts  by  a vertical  plane 
passing  lengthways  through  it,  they  would  be  found 
on  different  sides  of  the  plane. 

As  the  oesophagus  terminates  in  the  stomach  im- 
mediately after  it  has  passed  through  an  aperture  of 
the  diaphragm,  it  is  evident  that  the  stomach  must 
be  somewhat  fixed  at  that  place ; but  it  is  more  move- 
able  at  its  other  orifice ; for  the  extremity  of  the  duo- 
denum, into  which  it  is  continued,  is  moveable. 

Vol.  ix.  13 


98  External  Coat  of  the  Stomach. 

The  stomach  is  connected  to  the  concave  surface 
of  the  liver  by  the  reflexion  or  continuation  of  the 
peritoneum  which  forms  the  lesser  omentum.  This 
membrane,  after  extending  over  each  surface  of  the 
stomach  continues  from  its  great  curve  in  the  form 
of  the  large  omentum,  and  connects  it  to  different 
parts,  especially  to  the  colon.  There  are  likewise 
folds  of  the  peritoneum,  as  it  passes  from  the  dia- 
phragm and  from  the  spleen  to  the  stomach,  which 
appear  like  ligaments. 

Notwithstanding  these  various  connexions,  the 
stomach  undergoes  considerable  changes  in  its  posi- 
tion.  When  it  is  nearly  empty,  and  the  intestines 
are  in  the  same  situation,  its  broad  surfaces  are  pre- 
sented forwards  and  backwards  ; but  when  it  is  dis- 
tended, these  surfaces  are  presented  obliquely  up- 
wards and  downwards,  and  the  great  curvature  for- 
wards. When  its  anterior  surface  is  presented  up- 
wards, its  urifices  are  considerably  influenced  in  their 
direction,  and  the  oesophagus  forms  an  angle  with  the 
plane  of  the  stomach. 

The  stomach  is  composed  of  four  dissimilar  lamina, 
which  may  be  demonstrated  by  a simple  process  of 
dissection. 

There  is  first  a coat  or  external  covering  conti- 
nued from  the  peritoneum  : within  this,  and  connect- 
ed to  it  by  delicate  cellular  substance,  is  a coat  or 
stratum  of  muscular  fibres : contiguous  to  these  fibres, 
internally,  is  a layer  of  dense  cellular  substance,  call- 
ed a nervous  coat ; and  last  is  the  internal  coat  of  the 
stomach,  called  villous  or  fungous,  from  the  structure 
of  its  surface. 

The  external  or  first  coat  of  the  stomach,  as  has 
been  already  stated,  is  continued  from  the  concave 
surface  of  the  liver  to  the  lesser  curve  of  the  sto- 
mach in  two  delicate  lamina,  which  separate  when 
they  approach  the  stomach,  and  pass  down,  one  on 


i 


Muscular  and  Nervous  Coats  of  the  Stomach . 99 

each  side  of  it,  adhering  firmly  to  it  in  their  course : 
at  the  opposite  curve  of  the  stomach  they  again  unite 
to  form  the  great  omentum.  The  stomach  is  there- 
fore closely  invested  by  the  peritoneum  on  every  part 
of  its  surface  except  two  strips,  one  at  the  lesser  and 
the  other  at  the  greater  curvature.  These  strips  or 
uncovered  places  are  formed  by  the  separation  of  the 
lamina  above  mentioned,  which  includes  a triangular 
space  bounded  by  the  stomach  and  these  two  lamina. 
In  these  triangular  spaces,  at  each  curvature  of  the 
stomach,  are  situated  the  blood  vessels  which  run 
along  the  stomach  in  those  directions,  and  also  the 
glands  which  belong  to  the  absorbent  vessels  of  this 
viscus.  The  peculiar  arrangement  of  the  lamina  at 
this  place  is  particularly  calculated  to  permit  the  dila- 
tation of  the  stomach.  When  it  is  dilated  the  lamina 
are  in  close  contact  with  its  surface,  and  the  blood 
vessels  being  in  the  angle  formed  by  the  adhesion  of 
the  two  lamina  to  each  other,  are  so  likewise  : when 
it  contracts,  the  blood  vessels  appear  to  recede  from 
it,  and  the  lamina  are  then  applied  to  each  other. 

Where  the  peritoneum  thus  forms  a coat  to  the  sto- 
mach, it  is  stronger  and  thicker  than  it  is  between 
the  liver  and  stomach.  In  a recent  subject  it  is  very 
smooth  and  moist,  but  so  thin  that  the  muscular  fibres, 
blood  vessels,  &c.  appear  through  it.  If  it  is  care- 
fully dissected  from  the  muscular  coat,  it  appears 
somewhat  flocculent  on  that  surface  which  adhered 
to  the  muscular  fibres.  It  seems  to  be  most  abundant- 
ly furnished  with  serous  vessels ; but  it  has  been  as- 
serted by  Mascagni  and  Soemmering,  that  a large 
proportion  of  its  texture  consists  of  absorbent  ves- 
sels. The  cellular  substance  which  connects  this  to 
the  muscular  coat  appears  no  way  different  from  or- 
dinary cellular  membrane. 

The  Muscular  Coat  of  the  stomach  has  been  de- 
scribed very  differently  by  respectable  anatomists ; 


a 00  Internal  Coat  of  the  Stomach. 

some  considering  it  as  forming  three  strata  of  fibres? 
and  others  but  two.  If  the  stomach  and  a portion  of 
the  oesophagus  attached  to  it  be  moderately  distended 
with  air,  and  the  external  coat  carefully  dissected 
away,  many  longitudinal  fibres  will  appear  on  every 
part  of  it,  that  evidently  proceed  from  the  oesophagus; 
these  fibres  are  particulary  numerous  and  strong  on 
the  lesser  curvature  of  the  stomach. — Beside  the  lon- 
gitudinal fibres  there  are  many  that  have  a circular 
direction,  and  these  are  particularly  numerous  to- 
wards the  small  extremity  ; but  it  has  been  doubted 
whether  there  are  any  fibres  in  the  muscular  coat  of 
the  stomach  that  go  directly  round  it.  The  whole  sur- 
face of  the  stomach,  when  the  peritoneal  coat  is  re- 
moved, appears  at  first  view  to  be  uniformly  covered 
by  muscular  fibres ; but  upon  close  examination, 
there  are  interstices  perceived,  which  are  occupied 
with  firm  cellular  membrane. 

In  contact  with  the  internal  surface  of  the  mus» 
cular  coat  is  the  cellular  stratum , which  has  been 
called  the  JYervous  Coat  of  the  stomach.  It  is  dense 
and  firm,  of  a whitish  colour,  resembling  condensed 
cellular  membrane.  It  was  considered  as  different 
from  ordinary  cellular  membrane ; but  if  air  be  in- 
sinuated into  its  texture,  by  blowing  between  the 
muscular  and  villous  coats,  while  it  connects  them  to 
each  other,  it  exhibits  the  proper  appearance  of  cel- 
lular substance.  It  however  adds  greatly  to  the  ge- 
neral strength  of  the  stomach,  and  the  vessels  which 
terminate  in  the  villous  coat  ramify  in  it. 

The  internal  coat  of  the  stomach  in  the  dead  sub- 
ject is  commonly  of  a whitish  colour,  with  a tinge  of 
red.  It  is  named  villous,  from,  its  supposed  resem- 
blance to  the  surface  of  velvet.  It  has  also  been 
called  fungous,  because  the  processes  analogous  to 
the  villi  are  extremely  short,  and  its  surface  has  a 


Gastric  Liquor.  101 

granulated  appearance  5 differing  in  these  respects 
from  the  internal  surface  of  the  intestines.  It  is  con- 
tinued from  the  lining  membrane  of  the  oesophagus, 
but  is  very  different  in  its  structure.  Many  very 
small  vessels  seem  to  enter  into  its  texture,  which 
are  derived  from  branches  that  ramify  in  the  nervous 
coat.  It  is  supposed  by  several  anatomists  of  the 
highest  authority,  to  have  a cuticle  or  epithelium  ; 
and  it  is  said  that  such  a membrane  has  been  sepa- 
rated by  disease.  It  ought  however,  to  be  remem- 
bered, that  the  structure  of  the  villous  coat  of  the 
stomach  and  intestines,  is  essentially  different  from 
the  structure  of  the  cuticle. 

The  internal  coat  of  the  stomach  is  generally  found 
covered,  or  spread  over,  with  mucous,  which  can  be 
readily  scraped  off.  This  mucous  is  certainly  effus- 
ed upon  it  by  secreting  organs,  and  it  has  been  sup- 
posed that  there  were  small  grandular  bodies  exte- 
rior to  the  villous  coat,  which  furnished  this  secre- 
tion ; but  the  existence  of  such  bodies  is  very  doubt- 
ful, as  many  skilful  anatomists  have  not  met  with 
any  appearance  that  could  be  taken  for  glands,  ex- 
cept in  a very  few  instances,  which  would  not  be  the 
case  if  those  appearances  had  been  natural.  Pores, 
perhaps  the  orifices  of  mucous  follicles,  and  also  of 
exhalent  vessels,  are  very  numerous,  but  no  proper 
glandular  masses  are  attached  to  them.  Glands,  as 
have  been  already  said,  are  found  in  the  triangular 
spaces  between  the  lamina  of  the  peritoneum  at  the 
great  and  small  curvatures  of  the  stomach,  but  these 
evidently  belong  to  the  absorbent  system.  Besides 
the  mucous  above  mentioned,  a large  quantity  of  a 
different  liquor,  the  proper  Gastric  Juice , or  fluid  of 
the  stomach,  is  effused  from  its  surface.  It  nas  been 
supposed  that  this  fluid  is  furnished  by  the  small 
glandular  bodies  believed  to  exist  between  the  coats 


102 


The  Pylorus. 

of  this  origin  ; but,  admitting  the  existence  of  these 
glands,  they  are  not  sufficiently  numerous  to  produce 
so  much  of  it  as  is  found,  and  it  is  therefore  probable 
that  this  fluid  is  discharged  from  the  orifices  of  ex- 
halent  vessels  in  the  internal  surface. 

Much  information  respecting  the  gastric  liquor 
has  been  obtained  within  a few  years  past  by  the 
researches  of  physiologists,  and  they  are  generally 
agreed  that  it  is  the  principal  agent  in  the  effects 
produced  by  the  stomach  upon  alimentary  substan- 
ces.* - 

As  the  muscular  coat  of  the  stomach  frequently 
varies  its  dimensions,  trie  villous  and  nervous  eoats, 
which  have  no  such  power  of  contraction,  cannot  ex- 
actly fit  it.  They  therefore  generally  appear  larger, 
and  of  course  are  thrown  into  folds  or  rugae.  These 
folds  are  commonly  in  a longitudinal  direction  ; but 
at  the  orifices  of  the  stomach  they  are  arranged  in  a 
radiated  manner,  and  sometimes  they  are  observed 
in  a transverse  direction.  They  depend  upon  the 
contraction  of  the  muscular  fibres,  and  disappear  en- 
tirely when  the  stomach  is  laid  open  and  spread  out. 

At  the  lower  orifice  is  a circular  fold,  which  is 
permanent,  and  constitutes  the  valve  denominated 

* On  this  subject  the  student  may  consult  with  advantage. 

M.  Reaumur.  In  the  Memoirs  of  the  Academy  of  Sciences  for  1752. 

John  Hunter.  London  Philosophical  Transactions  for  1772  ; and  also 
his  observations  on  the  Animal  Economy,  1786. 

Dr.  Edward  Stevens.  Inaugural  Thesis  de  Alimentorum  Concoctione. 
Edinburgh,  1777. 

The  Abbe  Spalanzani.  Dissertations  relative  to  Natural  History,  Szc. 
The  first  volume  of  the  English  translation  contains  the  author’s  disserta- 
tions on  digestion,  and  also  the  first  paper  of  Mr.  Hunter,  and  the  Thesis 
of  Dr.  Stevens,  as  well  as  an  account  of  the  experiments  of  Mr.  Gosse  of 
Geneva. 

In  addition  to  these,  there  are  several  interesting  essays  in  the  French, 
German,  and  Italian  languages,  a compilation  of  which  is  to  be  found  in 
Johnson’s  “ History  of  the  progress  and  present  state  of  Animal  Chemistry.” 
See  Vol.  I.  page  180. 


Lymphatics  and  Nerves  of  the  Stomach.  1Q3 

Pylorous.  It  appears  like  a circular  septum  with  a 
large  foramen  in  its  centre,  or  like  a flat  ring.  The 
villous  and  nervous  coats  of  the  stomach  contribute 
to  this,  merely  by  forming  the  circular  fold  or  ruga  ; 
and  within  this  fold  is  a ring  of  muscular  fibres,  evi- 
dently connected  with  the  circular  fibres  of  the  mus- 
cular coat  of  the  stomach,  the  diameter  of  which  at 
this  place  is  not  larger  than  that  of  an  intestine  : the 
fibres  of  this  ring  seem  a part  of  the  muscular  coat 
projecting  into  the  cavity  of  the  stomach  and  duode- 
num. If  a portion  of  the  lesser  extremity  of  the  sto- 
mach and  the  adjoining  part  of  the  duodenum  be  de- 
tached, and  laid  open  by  a longitudinal  incision,  and 
then  spread  out  upon  a board,  the  internal  coat  can  be 
very  easily  dissected  from  the  muscular,  and  the  py- 
lorous will-  then  appear  like  a ridge  or  narrow  bundle 
of  muscular  fibres,  which  runs  across  the  extended 
muscular  membrane.  It  is  evident  that  when  the 
parts  are  replaced  so  as  to  form  a cylinder,  this  nar- 
row fasciculus  will  form  a ring  in  it.  Thus  arrang- 
ed, the  circular  fibres  can  readily  close  the  lower  ori- 
fice of  the  stomach. 

The  pylorus  separates  the  stomach  from  the  intes- 
tine duodenum  ; and  this  separation  is  marked  exte- 
riorly by  a small  circular  depression,  which  corres- 
ponds exactly  with  the  situation  of  the  pylorus. 

The  arteries  of  the  stomach  are  derived  from  the 
Coeliac,  the  first  branch  which  the  aorta  sends  off  to 
the  viscera  of  the  abdomen.  This  great  artery,  im- 
mediately after  it  leaves  the  aorta,  is  divided  into 
three  branches,  which  are  distributed  to  the  stomach, 
the  liver,  and  the  spleen,  and  are  called  the  Superior 
Cm'onary  or  Gastric,  the  Hepatic , and  the  Splenic. 
Beside  the  first  mentioned  branch,  which  is  distri- 
buted principally  to  the  neighbourhood  of  the  cardia 
and  to  the  lesser  curvature,  the  stomach  receives  a 
considerable,  branch  from  the  hepatic,  which  passes 


104  The  Intestines  in  general. 

along  the  right  portion  of  its  great  curvature,  and 
has  been  called  the  right  gastro-epiploic,  and  another 
from  the  spleen,  which  passes  along  the  left  portion 
of  the  great  curvature,  and  has  been  called  the  left 
gastro-epiploic.  In  addition  to  these  branches,  the 
splenic  artery,  before  it  enters  the  spleen,  sends  off 
several  small  arteries  to  the  great  extremity  of  the 
stomach,  which  are  called  vasa  brevia. 

These  vasa  brevia  generally  arise  from  the  main 
trunk  of  the  splenic  artery,  but  sometimes  from  its 
branches. 

•The  veins  which  receive  the  blood  from  these  ar- 
teries have  similar  names,  and  pursue  corresponding 
courses  backwards ; but  they  terminate  in  the  vena 
portarum. 

The  absorbent  vessels  of  the  stomach  are  very  nu- 
merous and  large  : they  pass  to  the  glands  which  are 
on  the  two  curvatures,  and  from  thence  to  the  thoracic 
duct.  It  is  an  important  fact  relative  to  the  history 
of  digestion,  that  there  are  good  reasons  for  doubting 
whether  chyle  commonly  passes  through  them,  not- 
withstanding their  number  and  size.* 

The  nerves  of  the  stomach  are  derived  principally 
from  the  two  great  branches  of  the  par  vagum,  which 
accompany  the  oesophagus  and  are  mostly  spent  upon 
this  organ.  It  also  receives  branches  from  several 
plexus,  which  are  derived  from  the  splanchnic  por- 
tions of  the  intercostal  nerves. 

SECTION  III. 

Of  the  Intestines. 

The  intestines  form  a Continued  canal  from  the 
pylorus  to  the  anus,  which  is  generally  six  times 

' Sabatier,  however,  in  one  subject  observed  white  lines  on  the  stomach, 
which  he  suspected  to  be  lacteals,  See  his  account  of  the  absorbents  of 
the  stomach. 


105 


Villous  Coat  of  the  Intestines, 

the  length  of  the  subject  to  which  they  belong.  Al- 
though the  different  parts  of  this  tube  appear  some- 
what different  from  each  other,  they  agree  in  their 
general  structure.  The  coats  or  lamina  of  which  they 
are  composed,  are  much  like  those  of  the  stomach, 
but  the  peritoneum  which  forms  their  external  coat 
does  not  approach  them  in  the  same  manner ; nor  is 
it  continued  in  the  form  of  omentum  from  the  whole 
tube,  there  being  only  a certain  portion  of  intestine, 
viz.  the  colon,  from  which  such  a process  of  perito- 
neum is  continued. 

The  Muscular  Coat,  like  that  of  the  stomach, 
consists  of  two  strata,  the  exterior  of  which  is  com- 
posed of  longitudinal  fibres,  which  adhere  to  the 
external  coat,  and  do  not  appear  very  strong.  The 
other  stratum,  consisting  of  circular  or  transverse 
fibres,  is  stronger,  as  the  fibres  are  more  numerous. 
It  is  observable  that  they  adhere  to  the  longitudinal 
fibres:  and  they  seldom  if  ever  form  complete  cir- 
cles. 

The  cellular  substance  immediately  within  the 
muscular  fibres  resembles  the  'nervous  coat  of  the 
stomach  in  its  firmness  and  density.  It  is  likewise 
so  arranged  as  to  form  many  circular  ridges  on  its  in- 
ternal surface,  which  support  to  a certain  degree  the 
permanent  circular  plaits  of  the  internal  coat,  called 
valvulze  conniventes. 

The  inner  surface  of  the  internal  coat  has  been 
commonly  compared  to  that  of  velvet,  and  the  coat 
is  therefore  called  villous ; but  there  is  certainly  a 
considerable  difference  between  these  surfaces  ; for 
if  a portion  of  the  small  intestine  be  inverted,  and 
then  suspended  in  perfectly  transparent  water,  in  a 
clear  glass,  and  examined  with  a strong  light,  it  will 
appear  like  the  external  surface  of  the  skin  of  a 
peach,  on  which  the  down  or  hair-like  processes  are 
not  so  close  as  those  on  velvet.  On  this  surface, 

Vol*  ii.  14 


106  Lieberkuhn  on  the  Villous  Coat. 

between  the  villi,  there  are  many  orifices  of  mucous 
follicles  and  of  exhaling  vessels.*  Exterior  to  the 
villous  coat,  many  very  small  glandular  bodies  are 
sometimes  found,  which  are  called  after  their  descri- 
bers  Glandulse  Brunneri  and  Peyeri. 

The  internal  coat  of  the  upper  portion  of  the  in- 
testinal tube  is  arranged  so  as  to  form  a great  num- 
ber of  transverse  or  circular  folds  or  plaits^  called 
Valvulse  Conniventes,  which  do  not  generally  extend 
round  the  intestine,  but  are  segments  of  circles;  they 
are  so  near  each  other  that  their  internal  edges, 
which  are  very  moveable,  may  be  laid  upon  the  folds 
next  to  them,  like  tiles  or  shingles.  It  is  evident 
that  this  arrangement  of  the  internal  coat  must  add 
greatly  to  its  length.  This  coat  is  extremely  vascu- 
lar, so  that  in  the  dead  subject  it  can  be  uniformly 
coloured  by  a successful  injection.  The  minute  struc- 
ture of  it  has  been  the  subject  of  very  diligent  inquiry. 
There  can  be  no  doubt  but  that  an  immense  number 
of  exhaling  and  of  absorbent  vessels  open  upon  it; 
but  there  are  many  different  opinions  respecting  the 
termination  of  one  set  of  vessels  and  the  commence- 
ment of  the  other. 

A very  interesting  account  of  the  Villous  Coat  was 
published  in  1744,  by  Lieberkuhn,  who  was  con- 
sidered by  his  contemporaries  as  a most  expert  prac- 
tical anatomist,  and  was  also  very  skilful  in  micro- 
scopical examinations,  for  which  he  was  particularly 
calculated,  as  his  natural  powers  of  vision  were  un- 
commonly strong.  In  his  essay  he  refers  to  his 
preparations,  which  were  at  Berlin,  and  which  ap- 
pear  to  have  excited  great  surprise  in  the  minds  of 

* It  appears  clearly,  from  the  account  of  Lieberkuhn,  that  the  ori- 
fices  or  terminations  of  the  arteries  on  the  intestines,  are  distinct  from 
the  follicles  ; for  he  forced  injection  from  the  arteries  into  the  cavity  of 
the  intestines,  and  found  the  follicles  still  filled  with  mucous.  He  then 
urged  the  injection  further,  and  filled  the  follicles,  or  forced  the  mucous 
out  of  tfeeat. 


Hewson  and  others  on  the  Villi.  107 

the  members  of  the  Academy  of  Sciences  of  Prussia, 
at  a time  when  one  of  the  first  anatomists  of  Europe, 
the  celebrated  Meckel,  was  of  their  number. 

According  to  this  account,  the  internal  surface  of 
the  small  intestines  abounds  with  villi,  and  with  the 
orifices  of  follicles.  These  villi  are  ^about  the  fifth 
part  of  a line  in  breadth.  In  each  of  them  is  a cavity 
filled  with  a soft  spungy  substance,  which  has  one 
or  more  orifices  communicating  with  the  intestines, 
and  from  which  also  proceeds  a lacteal  vessel.  On 
the  membrane  which  forms  this  cavity,  blood  vessels 
are  most  minutely  ramified.  This  cavity  he  calls  an 
ampullula,  and  supposes  it  to  constitute  the  principal 
part  of  the  villous.  By  injecting  the  arteries  of  the 
intestine,  he  was  able  to  pass  a fluid  through  the 
ampufluia  into  the  cavity  of  the  gut ; he  kept  a 
stream  of  air  in  this  way  passing  through  the  am- 
pullula until  it  was  nearly  dry  and  stiff,  and  then 
laid  it  open  with  a fine  instrument.  From  the  ap- 
pearances which  then  presented,  he  inferred  that  the 
cavity  of  the  ampullula  was  occupied  with  a spongy 
or  cellular  substance.  Around  each  villus  he  found 
a number  of  mucous  follicles,  which  often  were  filled 
with  a tenacious  mucous:  and  distinct  from  these 
must  be  the  exhalent  orifices,  which  discharged  a 
fluid  injected  by  the  arteries  without  passing  through 
the  mucous  follicles. 

Lieberkuhn  died  early,  and  left  but  one  essay  on 
this  subject,  which  was  originally  published  in  Hol- 
land, in  1744,  but  has  been  republished  by  the  Aca- 
demy of  Berlin,  in  their  Memoirs ; and  also  by  Mr. 
John  Sheldon,  of  London. 

This  account  of  Lieberkuhn  appears  to  have 
been  admitted  by  Haller ; but  it  has  been  rigidly 
scrutinized  by  some  of  the  anatomists  of  London, 
who  were  particularly  interested  with  the  subject; 
as  they  had  paid  great  attention  to  the  absorbent 


108  Fyfe  and  others  on  the  Villi . 

system,  and  were  very  successful  in  the  investiga- 
tion of  it. 

The  late  Mr.  Hewson,  whose  opinion  is  entitled  to 
the  greatest  respect,  rejected  the  idea  of  the  ampul- 
lula,  and  believed  that  the  villi  are  composed  of  net- 
works of  lacteals,  as  well  as  arteries  and  veins ; al- 
though he  added  that  (i  this  is  the  only  circumstance 
concerning  these  parts  in  which  he  should  differ  from 
this  very  acute  observer.”* 

Mr.  Sheldon  agrees  with  Lieberkuhn  : but  Mr. 
Cruikshank  asserts,  that,  “ in  some  hundred  villi, 
be  has  seen  the  lacteals  originate  by  radiated 
branches,  w hose  orifices  were  distinct,  on  the  surface 
of  the  villus.”  The  villus  being  transparent,  when 
the  intestine  was  immersed  in  water,  these  branches, 
filled  w ith  chyle  could  be  seen  passing  into  the  lac- 
teal. Mr.  Cruikshank  therefore  supposes  that  Lie- 
berkuhn was  mistaken,  and  that  the  spongy  cavity, 
or  ampullula,  was  the  common  cellular  membrane, 
connecting  together  all  the  arteries,  veins,  nerves, 
and  lacteals. 

It  seems  probable,  from  Mr.  Cruikshank’s  state- 
ment, that  Dr.  William  Hunter  held  the  same 
opinion  with  himself.  And  there  is  also  reason  to 
believe  that  Monro  the  second,  who  studied  anato- 
my at  Berlin,  held  a different  opinion  from  Lieber- 
kuhn. 

Mr.  Fyfe,  who  has  bedn  much  employed  in  the 
investigation  of  the  absorbent  system,  and  must  be 
perfectly  acquainted  with  the'preparations  of  Monro, 
asserts  that  each  lacteal  takes  its  rise  upon  one  of 
the  villi  by  numerous  short  radiated  branches,  and 
each  branch  is  furnished  with  an  orifice  for  imbibing 
chyle. 

bieveral  of  the  late  French  writers  adopt  the  opi- 


* See  Hewson’s  Experimental  Inquiries,  vol,  2,  page  171. 


109 


Division  of  ihe  Intestines „■ 

nion  of  Lieberkuhn  ; but  his  countryman  Soemmer- 
ing gives  a different  account  of  the  subject.  He  says, 
that,,  besides  the  blood  vessels,  each  villus  consists  of 
a fine  net-work  of  absorbent  vessels,  whose  orifices 
may  be  distinctly  recognised  ; and  that  from  six  to 
ten  of  these  orifices  are  sometimes  discovered. 

Mascagni,  who  has  published  the  most  extensive 
work  upon  the  absorbent  system  that  has  yet  appear- 
ed, supposes  Lieberkuhn  to  have  been  mistaken,  and 
confirms  the  description  of  Hewson  : but  he  also 
agrees  with  Hewson  in  his  opinion  of  the  general  ac- 
curacy of  Lieberkuhn. 

Notwithstanding  their  differences  respecting  the 
origin  of  thelacteals,  all  these  observers  have  agreed, 
that  the  orifices  which  communicate  with  the  lacteals 
are  on  the  villi ; and  that  these  villi  contain  also 
very  fine  ramifications  of  blood,  vessels.  They  have 
also  agreed,  that  the  surface  of  the  intestines  in  the 
intervals  of  the  villi  seems  occupied  with  the  orifices 
of  duets  or  of  exhalent  vessels.* 

Division  of  the  Intestines . 

Although  there  is  a considerable  degree  of  uni- 
formity in  the  structure  of  the  intestinal  canal,  dif- 
ferent parts  of  it  are  very  distinguishable  from  each 
other  by  their  exterior  appearance,  by  their  size, 
their  investments,  and  their  position. 

The  first  division  is  into  two  great  portions,  which 
are  very  different  from  each  other  in  their  diameter 
and  length,  as  well  as  their  situation  : the  first  por- 
tion being  much  smaller  in  diameter,  and  near  four 
times  the  length  of  the  other. 

* On  this  subject  the  student  will  consult  with  advantage,  Hewson’s 
Experimental  Inquiries,  vol.  2 ; Sheldon’s  History  of  the  Absorbent 
System,  part  1st ; Cruikshank  on  the  Anatomy  of  the  Absorbing  Ves- 
sels ; and  the  Historia  Yasorum  Lymphaticorum  Corporis  Hvtmani,  of 
Mascagni. 


110  Division  of  the  Intestines. 

These  portions  are  therefore  known  by  the  names 
of  Great,  and  Small  Intestines , and  the  line  of  sepa- 
ration between  them  is  very  strongly  marked ; for  they 
do  not  gradually  change  into  each  other,  but  the  al- 
teration in  size  and  in  exterior  appearance  is  very 
abrupt,  and  their  communication  is  not  perfectly  di- 
rect. A considerable  portion  of  the  Great  Intestine 
is  fixed  immoveably  in  the  abdomen,  while  a large 
part  of  the  Small  Intestine  is  very  moveable. 

Each  of  these  great  portions  of  the  intestinal  tube 
is  subdivided  into  three  parts.  Thus,  in  the  Small 
Intestine , there  is  a piece  at  the  commencement  call- 
ed Duodenum , a great  part  of  which  has  no  coat  from 
the  peritoneum,  and  is  immoveably  fixed  in  one  situa- 
tion ; while  all  the  remainder  of  the  small  intestine 
has  a uniform  covering  from  the  peritoneum,  and  is 
very  moveable.  This  last  piece,  notwithstanding 
its  exterior  uniformity,  is  considered  as  forming  two 
parts.  The  uppermost  two-fifths  form  one  part* 
which  is  called  Jejunum  ; and  the  remainder  is 
called  Ileum.  The  Great  Intestine  commences  in 
the  lower  part  of  the  right  side  of  the  abdomen,  and 
after  proceeding  up  that  side  crosses  over  to  the 
left,  along  which  it  descends  to  the  lower  part  again, 
when  by  a peculiar  flexure  it  proceeds  to  the  cen- 
tre of  the  posterior  margin  of  the  pelvis,  from  which 
it  passes  down  to  the  anus.  A short  portion  of  this 
intestine,  which  is  above  its  junction  with  the  ileum, 
is  called  Cxcum  ; the  part  which  proceeds  from  this, 
round  the  abdomen,  is  called  Colon  ; and  the  por- 
tion which  is  in  the  pelvis  is  called  Rectum. 

Of  the  Small  Intestines. 

Previous  to  the  description  of  the  small  intestines, 
it  is  necessary  to  observe,  that  the  Mesocolon,  or 
process  of  the  peritoneum  connected  to  the  trans- 
verse portion  of  the  colon,  forms  a kind  of  moveable 


Commencement  of  the  Small  Intestines . til 

and  incomplete  septum,  which  divides  the  abdomen 
into  an  upper  and  lower  apartment.  Above  this  sep- 
tum are  the  stomach,  with  the  commencement  of  the 
duodenum,  the  liver,  and  the  spleen  ; below  it.  that 
portion  of  the  small  intestine  which  is  called  jejunum 
and  ileum,  makes  its  appearance.  The  portion  of 
the  intestine  which  passes  from  the  stomach  to  the 
jejunum,  and  is  called  Duodenum , is  so  much  in- 
volved by  the  mesocolon,  that  the  greatest  part  of  it 
cannot  be  seen  without  dissecting  the  mesocolon  from 
its  connexion  with  the  back  of  the  abdomen. — For 
the  duodenum  proceeds  backwards  from  the  pylorus, 
and  passing  down  behind  the  peritoneum,  enters  a 
vacant  space  between  the  two  lamina  of  the  mesoco- 
lon ; it  proceeds  for  some  distance  in  this  space,  and 
then  emerges  on  the  lower  side  of  the  mesocolon. 
Here  the  duodenum  terminates,  and  the  small  intes- 
tine then  is  invested  by  the  peritoneum  in  such  man- 
ner as  to  form  the  mesentery,  which  continues  with  it 
throughout  its  whole  course  to  the  great  intestine. 
This  portion  of  the  intestine,  although  very  uniform 
in  its  exterior  appearance,  as  has  been  observed  be- 
fore, is  divided  into  Jejunum  and  Ileum  : the  jeju- 
num being  the  upper’  portion,  which  begins  at  the 
mesocolon  ; and  the  ileum  the  lower  portion,  which 
opens  into  the  great  intestine.  '> 

Of  the  Duodenum. 

The  length  of  this  intestine  is  equal  to  the  breadth 
of  twelve  fingers,  and  hence  its  name.  It  is  very 
different  from  the  rest  of  the  small  intestine,  not  only 
as  respects  its  position  and  investment  by  the  perito- 
neum, but  on  account  of  its  connexion  with  the  liver 
and  pancreas,  by  means  of  their  excretory  ducts, 
which  open  into  it.  From  this  connexion  with  these 
glands,  probably,  all  the  peculiarities  of  its  position 
are  to  be  deduced. 


112  Situation  of  the  Duodenum. 

When  the  stomach  is  in  its  natural  situation,  the 
pylorus  is  at  some  distance  from  the  back  of  the 
abdomen.  The  duodenum  proceeds  backwards 
from  this  point,  and  passes  near  the  neck  of  the 
gall-bladder,  being  here  connected  with  the  small 
omentum  ; it  then  curves  downwards,  and  descends 
before  the  right  kidney,  sometimes  as  low  as  the 
lower  part  of  it;  then  it  curves  again,  and  passes 
over  to  the  left:  after  it  has  arrived  at  the  left  side 
of  the  spine,  at  the  second  or  third  lumbar  vertebra, 
it  projects  forwards  and  downwards  to  form  the  je- 
junum. The  only  portion  of  this  intestine  which  is 
moveable,  is  that  which  is  in  sight  as  it  proceeds 
immediately  from  the  pylorus,  being  about  an  inch 
and  a half  or  two  inches  in  length.  The  remain- 
der is  connected  to  the  back  of  the  abdomen,  and  lies 
between  the  two  lamina  of  the  mesocolon.  In  its 
progress  its  passes  before  the  aorta  and  the  vena  cava, 
but  the  principal  branch  of  the  vena  portarum  is  be- 
fore it. 

The  duodenum  is  larger  in  diameter  than  any  other 
part  of  the  small  intestines,  and  has  a stronger  mus- 
cular coat.  Its  general  situation  admits  of  great  dilata- 
tion, and  it  has  been  called  a second  stomach.  Its  in- 
ternal coat  is  strictly  villous,  in  the  anatomical  sense 
of  the  word  ; and  its  folds,  the  valvulse  conniventes, 
begin  at  a small  distance  from  the  pylorus.  The  ori- 
fices of  many  mucous  ducts  are  to  be  seen  on  its  sur- 
face. It  is  supposed  that  some  of  these  are  the  ter- 
minations of  ducts  from  the  glands  of  Brunner,  which 
sometimes  appear  in  the  villous  coat,  or  very  close  to 
it  exteriorly ; being  small  flat  bodies,  with  a depres- 
sion in  the  centre,  and  a foramen  in  the  depression. 
They  are  sometimes  very  numerous  at  the  upper  ex- 
tremity of  this  intestine,  and  diminish  gradually  to- 
wards the  other  extremity. 

The  biliary  and  pancreatic  ducts  open  posteriorly 


113 


Jejunum  and  Ileum . 

into  the  duodenum,  rather  above  the  middle  of  it. 
The  orifice  of  these  ducts  is  generally  surrounded  by 
a small  tubercle,  which  is  oblong,  somewhat  rounded 
at  one  extremity,  and  pointed  at  the  other.  Some- 
times this  orifice  is  in  a plait,  like  one  of  the  valvulse 
conniventes.  Most  commonly  the  two  ducts  unite 
before  they  perforate  the  coat,  so  as  to  form  but  one 
orifice ; and  sometimes  they  open  separately,  but  al- 
ways very  near  to  each  other. 

Absorbent  vessels,  which  contain  chyle,  are  found 
on  the  duodenum. 

The  Jejunum  and  Ileum 

Are  situated  in  the  abdomen  very  differently  from 
the  duodenum.  When  the  cavity  is  opened,  and  the 
omentum  raised,  they  are  in  full  view  ; and  every 
portion  of  them,  except  the  two  extremities  and  the 
parts  near  them,  can  readily  be  moved.  This  free- 
dom of  motion  is  owing  to  the  manner  in  which  they 
are  invested  by  the  peritoneum  ; or  in  the  technical 
language  of  anatomy,  to  the  length  of  their  mesen- 
tery. They  agree  in  their  structure  with  the  general 
description  of  the  small  intestines,  but  their  muscular 
coat  is  rather  weaker  than  that  of  the  duodenum.  The 
valvulze  conniventes  are  very  numerous  and  large  in 
the  upper  part  of  the  tube,  or  the  jejunum  ; and  gra- 
dually diminish  in  number,  until  they  finally  disap- 
pear, in  the  lower  part  of  the  ileum.  The  villous 
coat  is  in  perfection  in  the  jejunum,  the  villi  being 
more  conspicuous  there  than  in  any  other  part  of  the 
intestinal  tube.  There  are  frequently  found,  exterior 
to  this  coat,  but  intimately  connected  with  it,  many 
small  glandular  bodies  of  a roundish  form,  which  are 
often  clustered  together  at  that  part  of  the  intestine 
which  corresponds  with  the  interstice  of  the  lamina 
of  the  mesentery.  They  are  called  Peyer’s  glands, 
Vol.  ii,  15 


114  Distinction  between  Jejunum  and  Ileum 

after  the  anatomists  who  first  described  them ; and  are 
supposed,  like  the  glands  of  Brunner,  to  secrete  mu- 
cus. If  a portion  of  the  jejunum  be  inverted,  and 
moderately  distended  with  air,  these  bodies  appear 
very  distinctly  in  it,  dispersed  at  small  distances  from 
each  other.  In  the  ileum  they  appear  in  small  clus- 
ters, which  often  have  the  appearance  of  disease. 

No  natural  line  of  separation  for  distinguishing  the 
jejunum  and  ileum  from  each  other,  is  to  be  found; 
but  these  names  are  still  retained  ; and  therefore  a 
rule  laid  down  by  Winslow  is  generally  adopted, 
viz.  to  name  the  first  two-fifths  of  the  tube  jejunum, 
and  the  remainder  ileum.  There  are,  however,  some 
important  differences  between  these  portions  of  the 
intestine. 

In  the  jejunum,  the  valvulae  conniventes  are  so  nu- 
merous, that  they  lie  in  contact  with  each  other,  as 
shingles  on  the  roof  of  a house ; in  the  ileum  they 
gradually  diminish  in  number,  and  finally  disappear. 
In  the  jejunum  the  villi  are  much  stronger  than  they 
are  in  the  ileum. 

It  is  very  difficult  to  acquire  a precise  idea  of  the 
arrangement  of  this  part  of  the  intestinal  tube,  while 
it  is  in  the  abdomen,  especially  if  it  be  much  distend- 
ed ; but  if  it  be  separated  at  each  extremity  from  the 
intestine  with  which  it  is  connected,  and  the  mesen- 
tery cut  off  from  the  back  of  the  abdomen,  and  the 
whole  then  spread  out  upon  a flat  surface,  it  will 
appear,  as  has  been  already  said,  that  the  intestine 
is  arranged  so  as  to  form  a semicircle  or  large 
curve;  the  concavity  of  which  is  opposite  to  the 
back  of  the  abdomen,  while  the  convexity  presents 
forward.  It  will  also  appear,  when  thus  placed 
upon  a table,  that  the  intestine,  while  connected 
with  the  mesentery,  is  laid  into  many  folds.  It  has 
been  supposed,  that  the  middle  portion  of  the  mesen- 
tery, and  the  intestine  connected  with  it,  is  generally 


Construction  of 'the  Mesentery . 115 

itn  the  umbilical  region  ; and  the  two  portions  on  the 
sides  of  it  are  in  the  iliac  regions  ; but  their  situation 
in  the  abdomen  varies  considerably  at  different  times. 
When  the  viscera  of  the  pejvis  are  empty,  a large 
portion  of  the  small  intestine  is  in  the  pelvis;  but 
when  those  viscera  are  filled,  the  intestine  is  in  the 
general  cavity  of  the  abdomen. 

The  Mesentery 

Is  a process  of  the  peritoneum,  which  is  formed  in 
the  manner  of  a plait  or  fold,  and  of  course  consists 
of  two  lamina.  These  lamina  proceed  from  the  back 
part  of  the  abdomen,  and  are  so  near  to  each  other, 
that  they  compose  one  substantial  process  ; having 
cellular  and  adipose  substance,  blood  vessels  and 
nerves,  with  absorbent  or  lacteal  vessels  and  their 
glands,  between  them. 

The  form  of  this  process,  when  it  is  separated 
from  the  back,  and  the  intestines  are  detached  from 
it,  is  somewhat  semicircular  : that  portion  of  its  mar- 
gin or  edge  which  corresponds  to  the  diameter  of  the 
semicircle,  is  connected  to  the  back  of  the  abdomen, 
and  called  the  root  of  the  mesentery;  the  edge,  which 
is  the  circumference  of  the  semicircle,  is  connected 
with  the  intestine.  The  edge  connected  with  the 
back  of  the  abdomen  is  commonly  about  five  or  six 
inches  in  length  -.  the  semicircular  edge,  instead  of  ex- 
tending fifteen  or  eighteen  inches,  the  ordinary  pro- 
portion, is  attached  to  a portion  of  intestine  some- 
times twenty-four  feet  in  length.  The  mesentery  on 
account  of  this  great  difference  between  its  diameter 
and  circumference,  has  been  compared  to  the  ruffle  of  a 
shirtsleeve;  its  roots  being  taken  for  the  plaited  edge 
of  the  ruffle,  and  the  circumference  for  its  loose  edge. 
But  the  comparison  is  not  precisely  accurate;  for  the 
mesentery  is  not  plaited  at  its  root,  but  perfectly 


116  Root  of  the  Mesentery . 

smooth,  and  free  from  every  kind  of  fold.  It  begins 
to  enlarge  towards  its  circumference,  and  enlarges  to 
that  degree,  that  it  falls  into  plaits  or  folds : precisely 
such  as  would  exist  in  a semicircular  piece  of  mem- 
brane about  six  inches  in  diameter,  if  a number  of 
simple  incisions,  of  about  an  inch  and  a half  in  length, 
were  made  in  a radiated  direction  from  its  circumfer- 
ence, and  if  portions  like  a sextant  or  quadrant  were 
taken  from  a circular  membrane  three  inches  in  di- 
ameter, and  united  by  their  edges  to  these  incisions, 
so  that  their  circumference  might  be  continuous  with 
the  circumference  of  the  large  semicircular  piece.  In 
this  case,  the  portions  like  quadrants  or  sextants 
would  assume  a folded  position  like  the  edge  of  the 
mesentery,  while  the  middle  of  the  semicircular  piece 
would  preserve  its  regular  form  without  folds  ; as  is 
the  case  with  the  mesentery  at  some  distance  within 
its  circumference.  By  many  additions  of  this  kind, 
the  circumference  of  a membrane,  which  was  original- 
ly a semicircle  of  five  or  six  inches,  may  be  extended 
so  as  to  exceed  greatly  that  of  the  mesentery.  It 
seems  of  course  impossible  to  form  an  accurate  mo- 
del of  the  mesentery  with  a single  piece  of  membrane 
or  paper ; but  it  may  be  easily  made  with  clay,  or 
any  ductile  substance.  A model  of  this  kind  must 
necessarily  be  folded  after  the  manner  of  the  mesen- 
tery ; and  its  circumference,  like  the  mesentery,  would 
appear  as  if  formed  of  portions  of  the  circumference 
of  smaller  circles  united  to  each  other.* 

The  root  of  the  mesentery  commences  with  the 
jejunum  on  the  lower  side  of  the  mesocolon,  at  the 
left  of  the  spine,  and  extends  downwards  near  to 
the  right  iliac  region  $ crossing  the  spine  obliquely. 

* A model,  upon  the  plan  first  mentioned,  was  invented  by  Dr.  J.  G. 
Shippen.  It  has  been  proposed,  I believe  by  M.  Gavard,  to  make  one 
with  a single  piece  of  buckskin,  of  a semicircular  formf  by  stretching  it  at 
the  circumference! 


Appearances  of  the  C cecum  and  Coton.  117 

When  it  is  examined  in  its  natural  situation,  the  peri- 
toneum is  found  continued  from  the  back  of  the  ab- 
domen to  the  intestine  ; it  then  surrounds  the  intes- 
tine, and  continues  from  it  to  the  back  of  the  abdo- 
men again.  There  must  therefore  be  two  lamina  of 
peritoneum  in  the  mesentery,  and  there  must  be  a 
small  portion  of  intestine  answering  to  the  interstice 
between  these  lamina,  which  is  not  covered  by  the 
peritoneum.  The  blood  vessels,  and  absorbent  or 
lacteals,  pass  most  commodiously  to  the  intestines 
between  these  lamina ; for  they  are  connected  with 
large  trunks  that  lie  on  or  near  the  spine,  and  the 
root  of  the  mesentery  commences  there. 

The  glands  connected  with  the  lacteals  or  absorb- 
ents are  very  conspicuous  in  the  mesentery,  and  are 
commonly  called  mesenteric  glands.  They  are  of 
different  sizes,  from  more  than  half  an  inch  to  one  or 
two  lines  in  diameter.  They  are  very  numerous, 
and  scattered  irregularly,  but  are  seldom  observed 
very  near  to  the  intestine.  They  are  often  enlarged 
in  consequence  of  disease,  especially  in  children. 

The  nerves  of  the  small  intestines  which  are  de- 
rived principally  from  the  superior  mesenteric  plex- 
us, are  also  to  be  found  here. 

The  adipose  matter  between  the  lamina  of  the  me- 
sentery is  very  often  in  a large  quantity,  but  varies, 
in  proportion  to  the  general  quantity  of  adeps  in  the 
subject. 

OF  THE  GREAT  INTESTINES. 

The  Ceecum  and  Colon 

Are  very  different  from  the  small  intestines  in 
many  respects.  They  are  much  larger  in  diameter. 
Their  external  surface  is  marked  by  three  longitudi- 
nal bands  of  a light  colour,  which  extend  the  great- 
est part  of  their  length,  and  are  placed  nearly  at 


118  Position  of  the  Caecum, 

equal  distances  from  each  other.  The  spaces  be- 
tween these  bands  are  marked  by  transverse  inden- 
tations, which  pass  from  one  band  to  the  other  at 
short  but  unequal  distances.  At  these  indentations 
the  coats  of  the  intestine  are  pressed  inwards,  as  if  a 
fine  thread  had  been  drawn  round  it  externally? 
while  the  spaces  between  them  are  full  and  tumid? 
and  on  this  account  are  called  cells. 

The  great  intestine,  with  these  appearances?  be- 
gins, as  has  been  already  observed,  in  the  right  iliac 
region,  by  a rounded  end  which  rests  on  the  fossa 
or  concave  surface  formed  by  the  costa  of  the  ileum ; 
from  this  it  is  continued  upwards  in  the  right  lum- 
bar region,  anterior  to  the  kidney,  until  it  arrives 
near  the  liver,  when  it  forms  a curve?  and  passes 
directly  across  the  abdomen  to  the  left  side.  In  this 
course  it  approaches  so  near  to  the  under  side  of 
the  liver,  that  it  is  often  in  contact  with  it,  and  with 
the  gall-bladder,  which,  after  death,  tinges  it  with  a 
yellow  colour.  On  the  left  side  it  passes  dowm  the 
lumbar  region,  before  the  kidney,  to  the  left  iliac 
region ; here  it  is  curved  so  as  to  resemble  the 
Roman  letter  S,  inverted  ; this  curve  generally  car- 
ries it  to  the  right  side  of  the  spine,  and  then  brings 
it  back  to  the  centre  of  the  sacrum.  Here  the  in- 
testine changes  its  course,  and  passing  into  the 
pelvis,  continues  downward,  in  contact  with  the 
sacrum  and  coccygis,  and  partaking  of  the  curvature 
of  those  bones,  until  it  terminates  at  the  anus,  where 
it  is  connected  with  the  sphincter  and  levator  ani 
muscles. 

About  two  inches  from  the  commencement  of  the 
great  intestine  the  ileum  opens  into  it  laterally  ; and 
all  that  portion  which  is  between  its  commencement 
and  the  insertion  of  the  ileum  is  termed.  Caecum,  or 
the  blind  intestine:  that  part  of  the  great  tube? 
which  is  included  in  its  course  from  the  insertion  of 


119 


Structure  of  the  Colon . 

the  ileum  to  the  posterior  part  of  the  brim  of  the 
pelvis,  is  called  Colon ; and  the  remainder,  or  the 
part  which  is  contained  in  the  pelvis,  is  termed  i?ee- 
turn. 

The  Csecurn  is  nearly  as  wide  as  it  is  long  ; it  is 
fixed  in  the  right  iliac  fossa  by  the  peritoneum, 
which  invests  it  so  that  the  great  body  of  the  intes- 
tine projects  from  the  surface  of  the  fossa  covered 
by  the  peritoneum  ; but  a portion  is  in  close  con- 
tact with  the  surface,  and  connected  to  it  by  celhi" 
lar  membrane.  Its  external  surface,  covered  by  the 
peritoneum,  is  marked  by  two  of  the  bands  or 
stripes  before  mentioned,  which  proceed  on  it  length- 
ways. These  bands  are  in  full  view,  but  the  third 
band  is  generally  on  that  part  of  the  intestine  which 
rests  on  the  iliac  fossa,  and  is  therefore  out  of  sight. 
At  the  rounded  extremity  of  the  csecurn,  situated 
anteriorly  and  internally,  is  a small  process  resem- 
bling an  earth-worm  in  form  and  size  : this  is  there- 
fore called  Jippendicula  Vermiformis.  It  is  hollow 
and  communicates  with  the  cavity  of  the  csecurn  at 
the  place  of  junction  ; and  like  the  csecurn,  has  its 
other  extremity  closed  up.  It  is  composed  of  the 
same  number  of  coats  and  has  the  same  structure  as 
the  great  intestine  : its  length  varies  from  two  to  four 
inches. 

The  longitudinal  bands  above  mentioned  commence 
at  the  junction  of  this  appendix  with  the  csecurn,  and 
continue  throughout  the  extent  of  the  colon.  They 
appear  to  be  formed  by  some  of  the  longitudinal  fibres 
of  the  muscular  coat,  which  are  arranged  close  to  each 
other.  These  fibres  seem  to  be  shorter  than  the  coats 
of  the  intestine,  and  the  interior  coats  adhere  firmly 
to  them.  Thus  are  produced  the  indentations  and 
cells ; for  if  the  bands  are  divided  transversely,  the 
indentations  disappear,  and  the  surface  of  the  intes- 


120 


Valve  of  the  Colon. 

tine  becomes  uniform.  One  of  these  bands  is  cover* 
ed  by  the  mesocolon. 

The  circular  or  transverse  fibres  of  the  muscular 
coat  of  the  csecum  and  colon  are  very  delicate,  and 
not  numerous. 

The  internal  coat  differs  materially  from  that  of  the 
small  intestines,  although  at  first  view  they  seem  to 
resemble  each  other : for  if  a portion  of  the  ileum  and 
of  the  colon  be  inverted  and  suspended  in  water,  no 
villi  can  be  seen  with  the  naked  eye  on  the  internal 
coat  of  the  colon,  while  those  of  the  ileum  are  very 
visible.  The  glands  exterior  to  this  coat  are  larger 
than  those  on  the  small  intestines. 

Instead  of  valvulse  conniventes,  are  the  ridges  made 
by  the  indentations  or  depressions  above  described, 
which  separate  the  incomplete  cells  from  each  other. 
These  ridges  differ  essentially  from  the  valvular  con- 
niventes, because  all  the  coats  of  the  intestine  are  con- 
cerned in  their  formation,  whereas  the  valvulse  conni- 
ventes are  formed  by  the  villous  coat  only ; they  also 
project  into  the  cavity  of  the  intestine,  while  the  val- 
vulse are  laid  on  its  surface.  They  pass  only  from 
one  longitudinal  band  to  another,  and,  in  consequence 
of  this,  the  cells  are  small,  and  the  position  of  each 
band  is  very  evident  when  the  intestine  is  laid  open. 

The  communication  of  the  ileum  with  the  great 
intestine  has  been  already  stated  to  be  on  the  left 
side  of  it,  about  two  inches  from  its  commencement. 
The  aperture  is  so  constructed,  that  it  is  considered 
as  a valve,  and  is  called  the  Valve  of  Bauhin,  or  of 
Tulpius,  after  the  anatomists  who  have  described 
it.*  The  appearance  of  the  aperture  is  as  follows: 
If  the  csecum,  with  a small  portion  of  the  ileum  and 

* Posthius  in  1566;  Vidus  Vidius  about  1569;  Alberti  in  1581,  and  Varo- 
lius  who  died  in  1575,  each  lay  claims  to  the  discovery  of  it.  Bauhin’s 
claims  are  in  1579.  Em 


Structure  of  the  Valve  of  the  Colon.  • 121 

of  the  colon,  be  separated  from  the  other  intestines, 
and  kept  in  an  inflated  state  until  it  be  so  dry  as  to 
preserve  its  form  when  opened,  and  then  if  the  cae- 
cum and  colon  be  laid  open  opposite  to  the  aperture 
of  the  ileum,  a large  transverse  ridge,  resembling 
some  of  the  ridges  or  folds  just  described,  will  be 
seen  projecting  into  the  cavity  of  the  intestine.  In 
the  internal  edge  of  this  fold  is  a long  slit  or  opening, 
which  forms  the  communication  between  the  two  in- 
testines. It  is  obvious  that  the  form  of  this  fold  must 
be  that  of  a crescent ; and  that  its  two  surfaces  with 
the  slit  between  them,  must  have  the  appearance  of 
two  lips,  which  would  readily  permit  a fluid  or  sub- 
stance of  soft  consistence  to  pass  from  the  ileum  into 
the  great  intestines,  but  must  impede,  if  not  prevent, 
its  passage  back ; especially  if  the  large  intestines 
were  distended,  as  then  the  lips  would  be  pressed 
against  each  other. 

When  the  peritoneal  coat  is  dissected  from  each 
of  the  intestines  at  their  place  of  junction,  and  this 
structure  is  then  examined  from  without , it  appears 
as  if  a transverse  or  half  circular  indentation  had 
been  formed  by  the  villous  coat  of  the  great  intestine, 
and  that  the  internal  coat  of  the  extremity  of  the 
ileum  was  pressed  into  this  indentation,  and  united 
to  the  internal  coat  of  the  great  intestine  which  form- 
ed it;  while  there  was  a slit,  both  in. the  indentation 
and  in  the  end  of  the  ileum,  which  formed  a commu- 
nication between  the  eavityof  the  great  intestine  and 
the  ileum.  The  longitudinal  fibres  of  both  intestines, 
as  well  as  their  external  coats,  seemed  to  be  united, 
so  as  to  form  a common  cover  for  them ; while  the 
circular  fibres  were  blended  in  the  two  portions  of 
the  indentation  which  form  the  lips  of  the  orifice. 

This  orifice  is,  of  course,  transverse  with  respect 
to  the  intestine.  It  has  been  observed,  that  there 
was  a difference  in  the  thickness  and  strength  of  the 

VoLj  ii,  16  ' 


122  Position  of  the  Rectum . 

two  lips  or  valves ; that  the  lower  valve  was  the 
strongest,  and  appeared  to  have  the  largest  propor- 
tion of  muscular  fibres  in  its  composition.  At  the 
extremities  of  the  orifice,  and  near  each  end  of  the 
fold  or  ridge,  are  tendinous  fibres,  which  give 
strength  to  the  structure  ; they  are  called  the  Reti- 
nacula of  Morgagni,  as  they  were  first  described  by 
that  anatomist. 

There  is  great  reason  for  believing  that  this  valve 
cannot  prevent  the  retrograde  motion  of  the  contents 
of  the  intestines  in  all  cases  ; for  in  some  instances 
of  hernia  and  of  colic,  matter  perfectly  stercoraceous 
has  been  vomited,  and  the  probable  inference  from 
such  a state  of  the  ejected  matter  is,  that  this  matter 
has  been  in  the  large  intestines.  It  is  also  said,  that 
suppositories  and  enemata  have  been  discharged  by 
vomiting. 

On  the  right  and  left  sides  of  the  abdomen,  the 
colon  is  in  close  contact  with  the  posterior  surface  of 
the  cavity.  The  peritoneum,  which  covers  this  sur- 
face, extends  over  the  intestine  also,  and  thus  retains 
it  in  its  position  . The  great  arch  of  the  colon,  which 
is  loose  and  moves  far  from  the  back  of  the  abdomen, 
is  invested  by  the  two  lamina  of  the  omentum,  which, 
after  surrounding  it,  unite  again  and  form  the  meso- 
colon. Connected  with  the  exterior  surface  of  the 
colon  are  many  processes,  composed  of  adipose  mem- 
brane, varying  in  length  from  half  an  inch  to  an  inch 
and  a half : these  appear,  to  be  of  the  nature  of  the 
omentum,  and  are  therefore  generally  denominated 
Appendices  Epiploicsc. 

The  Rectum. 

After  forming  the  sigmoid  flexure,  the  colon  ter- 
minates; and  the  rectum  begins  opposite  to  the  lower 
Surface  of  the  last  lumbar  vertebra,  and  nearly  in 
contact  with  it ; from  this  it  proceeds  downwards, 


123 


Structure  of  the  Rectum. 

forming  a curve  like  the  sacrum,  until  it  terminates 
at  the  anus,  where  it  is  invested  with  the  muscles 
called  the  sphincter,  and  levator  ani.  It  is  called 
rectum,  because  in  this  course  it  is  supposed  not  to 
incline  to  either  side ; but  it  is  often  found  on  one 
side  of  the  middle  line.* 

This  intestine  being  in  contact  with  the  posterior 
surface  of  the  pelvis,  is  covered,  on  its  anterior  sur- 
face only,  by  the  peritoneum  which  lines  the  poste- 
rior surface  of  the  pelvis ; and  it  is  fixed  in  this  situ- 
ation  by  the  peritoneum,  as  the  colon  is  on  the  right 
and  left  sides  of  the  abdomen,  but  more  loosely;  and 
therefore  the  term  Mesorectum  has  sometimes  been 
applied  to  that  portion  of  the  peritoneum  which  is 
analogous  to  the  mesentery  and. mesocolon.  The  pe- 
ritoneum does  not  extend  to  the  end  of  th'e  rectum ; 
for  it  is  reflected  at  the  lower  part  of  the  pelvis  from 
the  rectum  to  the  bladder,  or  uterus,  and  does  not 
line  the  bottom  of  the  pelvis  ; so  that  the  lower  part 
of  this  intestine,  as  well  as  of  the  other  viscera  of 
the  pelvis,  is  below  the  peritoneum,  and  not  connect- 
ed with  it. 

The  muscular  coat  of  the  rectum  is  much  thicker 
and  stronger  than  that  of  any  other  intestine.  The 
strata  of  longitudinal  and  circular  fibres  which  com- 
pose it  are  very  distinct  from  each  other.  The  lon- 
gitudinal fibres  are  most  numerous,  and  terminate  at 
the  insertion  of  the  fibres  of  the  levator  ani  muscle. 
The  lower  circular  fibres  are  intimately  connected 
with  the  sphincter  ani. 

The  internal  coat  is  very  vascular,  but  the  villous 
structure  is  not  apparent.  Mucous  follicles  are  also 
very  numerous;  and  there  are  likewise  some  distinct 
glandular  bodies  exterior  to  this  coat,  which  vary  in 
size  in  different  subjects. 

* Morgagni  and  Haller  supposed  it  to  be  commonly  on  the  left  of  the 
middle  line:  and  Sabatier  on  the  right. 


124  Absorbents  and  JYerves  of  the  Intestines. 

The  quantity  of  mucous  discharged  from  the  rec- 
tum in  certain  cases  of  disease,  is  sometimes  very 
great.  The  internal  coat,  in  consequence  of  the  con- 
traction of  the  circular  fibres  exterior  to  it,  some- 
times forms  longitudinal  folds,  which  have  been 
called  its  columns  ; these  often  disappear  when  the 
intestine  is  opened  lengthways  and  spread  out.  By 
the  contraction  of  the  longitudinal  fibres,  the  internal 
coat  is  often  thrown  into  folds  or  doublings,  that 
must  assume  a transverse  or  circular  direction  ; they 
occasionally  pass  down  through  the  sphincter,  and 
form  the  prolapsus  ani.  The  rectum  is  most  plenti- 
fully supplied  with  blood  vessels,  to  be  described 
hereafter;  and  it  may  be  observed,  that,  on  the  low- 
er part  of  the  internal  coat,  the  veins  are  particular- 
ly numerous. 

The  internal  coat  of  the  rectum  terminates  ab- 
ruptly just  within  the  anus,  and  is  united  to  a pro- 
duction of  the  skin,  which,  like  the  covering  of  the 
lips,  is  very  delicate  and  vascular,  and  has  an  epi- 
thelium, or  very  thin  cuticle*  spread  over  it.  The 
levator  and  sphincter  ani  muscles,  with  which  the 
termination  of  the  rectum  is  invested,  are  described 
in  the  first  volume.  , 

The  Absorbents  of  the  Intestines  are  commonly 
denominated  Lacteals .*  They  originate  on  the  in- 
ternal surfaces  of  these  viscera,  as  has  been  already 
described.  After  passing  through  the  lymphatic 
glands,  which  are  so  numerous  on  the  mesentery, 
they  generally  unite  and  form  one  of  the  great  trunks 
which  compose  the  thoracic  duct.  It  is  asserted, 
that  some  of  the  absorbent  vessels  of  the  lower  in- 
testines unite  to  the  lymphatics  of  the  loins. 

* The  lacteals  were  first  observed  by  Erasistratus  and  Herophilus,  of 
the  school  of  Alexandria,  during  the  reign  of  the  Plotemies  ; and  subse- 
quently by  Aselli,  of  Pavia,  in  1622,  the  knowledge  of  them  having  been 
lost  for  1900  years. — Ed. 


Origin  and  Arrangement  of  the  Omentum.  125 

The  Nerves  of  the  Intestines  are  principally  de- 
rived from  the  intercostals,  or  great  sympathetics 
From  each  of  these  nerves,  while  they  are  in  the  tho- 
rax, an  important  branch,  called  the  ramus  splanch- 
nieus,  arises.  These  splanchnic  branches  pass  through 
the  diaphragm,  and  are  the  chief  contributors  to  the 
ganglions  and  plexuses  formed  in  the  abdomen.  A 
plexus,  derived  from  this  source  surrounds  the  supe- 
rior mesenteric  artery,  and  another  the  inferior  me- 
senteric ; and  from  these  proceeds  the  nerves  of  the 
intestines. 

The  Omentum 

Requires  a separate  description,  although  several 
circumstances  connected  with  its  structure  have  been 
already  noticed.  It  often  varies  in  its  position;  but 
when  it  is  rendered  firm  by  a quantity  of  adipose  mat- 
ter, it  is  spread  over  the  intestines  like  an  apron,  ex- 
tending from  the  lower  edge,  or  great  curvature  of 
the  stomach,  towards  the  bottom  of  the  abdomen. 

As  has  been  already  said,  it  is  an  extension  of  the 
peritoneum,  in  two  lamina,  from  the  concave  surface 
of  the  liver  to  the  lesser  curvature  of  the  stomach  ; 
and  these  lamina,  after  surrounding  the  stomach, 
come  in  contact  with  each  other  near  its  great  curva- 
ture. From  this  portion  of  the  stomach,  from  the 
commencement  of  the  duodenum,  and  also  from  the 
spleen,  the  Omentum , composed  of  two  lamina  de- 
scends over  the  colon  and  the  small  intestines  more 
or  less  low  into  the  abdomen ; it  is  then  folded  back- 
wards and  upwards,  and  is  continued. until  it  meets 
the  great  arch  in  the  colon  : here  the  lamina  again 
separate  and  enclose  that  portion  of  the  intestine,  on 
the  posterior  side  of  which  they  again  approach  each 
other,  and  form  a membrane  like  the  mesentery,  of 
two  lamina,  which  passes  from  the  concave  or  pos- 
terior surface  of  the  colon  to  the  back  of  the  abdo- 


126  Origin  and  Arrangement  of  the  Omentum . 

men,  where  it  is  continued  into  the  membrane  which 
lines  that  surface.  This  last  portion  is  the  Mesoco- 
lon: the  portion  between  the  liver  and  stomach  is 
called  the  Omentum  of  Winslow , or  the  lesser 
omentum;  and  the  great  portion  between  the  sto- 
mach and  colon  is  called  the  Great  Omentum , or  the 
omentum  gastro  colicum.  There  is  also  a process 
of  peritoneum  continued  from  that  portion  of  the 
colon  which  is  on  the  right  side  of  the  abdomen,  and 
from  the  caecum,  which  extends  to  some  distance  ; 
it  is  formed  of  two  lamina,  that  compose  a cavity  of 
an  angular  form.  This  has  been  called  the  Omen- 
tum Colicum. 

The  great  and  small  omentum,  with  a portion  of 
the  peritoneum  on  the  back  of  the  abdomen,  form  a 
sac,  which  encloses  a distinct  cavity  in  the  abdomen. 
The  anterior  part  of  this  sac  is  composed  of  two 
lamina,  and  between  these  lamina  are  the  stomach 
and  the  great  arch  of  the  colon.  This  cavity,  form- 
ed by  the  two  omenta,  communicates  with  the  gene- 
ral cavity  of  the  abdomen  by  a foramen  of  a semicir- 
cular form,  called  the  Foramen  of  Winslow,  which 
is  behind  the  great  cord  of  the  vessels  that  go  to  the 
liver. 

The  omentum  is  so  delicate  in  structure,  that 
when  free  from  fat,  it  is  very  liable  to  laceration 
merely  by  adhering  to  the  fingers,  if  they  are  dry. 
Winslow  therefore  advised  that  some  unctuous  sub- 
stance should  be  rubbed  on  the  hands,  before  they 
were  applied  to  it. 

The  appearance  of  the  great  omentum  is  very  dif- 
ferent in  different  persons.  In  the  emaciated,  it 
appears  like  a delicate  transparent  membrane  ; in 
the  corpulent,  it  is  like  a broad  mass  of  adeps,  which 
sometimes  is  very  thick.  When  it  is  thus  loaded 
with  adeps,  it  is  most  commonly  spread  over  the 
small  intestines  : when  it  is  free  from  fat,  it  is  often 


Varieties  in  the  Appearance  of  the  Omentum.  127 

compressed  together,  so  as  to  form  a small  mass  near 
the  arch  of  the  colon,  on  the  left  side. 

The  principal  blood  vessels  of  the  omentum  are 
derived  from  those  of  the  stomach,  and  are  called  gas- 
tro  epiploic  arteries  and  veins. 

The  use  of  this  membrane  in  the  animal  economy 
has  not  been  ascertained  with  certainty.  It  seems 
probable  that  one  of  its  principal  objects  is  to  protect 
the  small  intestines,  and  lessen  the  friction  consequent 
upon  their  motion ; but  it  has  been  supposed  to  an- 
swer several  other  important  purposes.* 

* See  Halleri  Elementa  Physiologic,  vol.  vi.  page  381. 

Gavard.  Traite  de  Splanchnologie,  page  350. 

Dr.  James  Rush’s  Inquiry  into  the  use  of  the  Omentum. 


CHAPTER  III. 


OF  THE  LIVER,  THE  PANCREAS,  AND  THE  SPLEEN. 

SECTION  L 

Of  the  Liver. 

This  largest  viscus  of  the  abdomen,  when  in  a 
healthy  condition,  is  of  a reddish-brown  colour.  If  it 
is  taken  out  of  the  subject,  and  laid  on  a flat  surface, 
it  is  flat,  but  in  the  abdomen  it  is  convex  and  concave. 

It  is  situated  in  the  right  hypochondriac  region, 
which  it  occupies  entirely ; and  extends  through  the 
upper  portion  of  the  epigastric  into  the  left  hypochon- 
driac region.  Being  placed  immediately  under  the 
diaphragm,  and  in  close  contact  with  it,  as  well  as  with 
the  inner  surface  of  the  right  hypochondriac  region, 
it  partakes  of  their  form,  and  is  convex  above  and 
concave  below.  When  thus  situated,  it  is  of  an  irre- 
gular figure,  between  the  circular  and  the  oval,  but  it 
is  broader  at  the  right  extremity  than  at  the  left,  and 
very  irregular  in  thickness.  The  edge  or  margin 
which  is  in  contact  with  the  posterior  part  of  the  right 
hypochondriac  region,  is  very  thick.  It  gradually  be- 
comes thinner  towards  the  left,  and  also  towards  the 
front;  so  that  the  right  margin,  and  a large  portion 
of  the  posterior  margin,  is  very  thick,  while  the  left 
and  the  anterior  margin  is  thin. 

The  upper  convex  surface  of  the  liver,  when  in 
its  natural  situation,  is  smooth : the  lower  concave 
surface  is  marked  by  several  grooves  or  fissures  and 
eminences.  One  of  these,  called  the  Umbilical  or 
the  great  fissure,  commences  at  a notch  in  the  ante- 


129 


Lobes  and  Fissures  of  the  Liver. 

rior  edge  of  the  liver,  to  the  left  of  the  middle,  and 
continues  to  the  posterior  edge.  At  the  commence- 
ment of  this  fissure  the  umbilical  ligament  enters  ; 
and  at  the  termination,  or  near  it,  the  vena  cava  is 
situated.  Opposite  to  this  fissure,  on  the  upper  or 
convex  surface,  is  a ligament  passing  from  the  dia- 
phragm to  the  liver,  which  is  called  the  falciform. 
The  fissure  and  the  ligament  divide  the  liver  into  its 
two  great  lobes,  the  Right  and  Left . 

Another  great  fissure , called  the  transverse  or 
principal,  commences  in  the  right  lobe  and  extends 
to  the  left,  crossing  the  first  mentioned  fissure  at 
right  angles,  and  extending  a very  short  distance 
beyond  it.  It  is  very  deep,  and  rather  nearer  to 
the  posterior  than  the  anterior  edge  of  the  liver.  In 
this  fissure,  near  to  its  right  extremity,  the  great 
vein,  called  vena  portarum,  and  the  hepatic  artery 
enter,  and  the  excretory  duct  of  the  liver,  commonly 
called  the  hepatic  duct,  comes  out.  About  the  mid- 
dle of  the  fissure  are  two  prominences,  one  on  each 
side ; these  were  called  the  portae,  or  gates  of  the 
liver,  and  hence  the  great  vein  was  called  vena  por- 
tarum. This  vein  has  two  very  large  rectangular 
branches,  which  constitute  what  is  called  the  sinus 
of  the  vena  portarum,  and  they  occupy  the  principal 
extent  of  the  fissure. 

The  liver  is  in  close  contact  with  the  vena  cava 
behind;  and  there  is  either  a groove  in  it  for  the  pas- 
sage of  the  vein,  or  this  great  vessel  is  completely  en- 
closed by  it.  There  is  also  an  excavation  on  the 
lower  surface  of  the  liver,  which  is  occupied  by  a 
portion  of  the  gall  bladder. 

Besides  the  great  lobes  above  mentioned,  there 
are  also  two  or  three  prominent  parts  on  the  concave 
surface,  which  are  denominated  lobes.  One  of  these, 
called  Lohulus  Spigelii,  is  oblong,  with  two  sides, 
and  an  angle  continued  along  its  whole  length, 
Vol,  II.  17 


130 


Ligaments  of  the  Liver „ 

which  extends  from  the  transverse  fissure  to  the  pos- 
terior margin  of  the  liver.  It  is  situated  between 
the  posterior  part  of  the  transverse  fissure,  or  ductus 
venosus,  and  the  vena  cava. 

The  anterior  extremity  of  this  lobe,  which  forms 
one  of  the  margins  of  the  transverse  fissure,  is  some- 
what bifurcated,  and  has  been  called  lobulus  caudatus. 
The  largest  portion  of  the  bifurcated  end  forms  a pro- 
cess like  a papilla,  and  is  one  of  the  portae. 

Between  the  umbilical  fissure  and  the  depression 
for  the  gall  bladder  is  a protuberant  space,  which 
varies  from  an  inch  and  a quarter  to  two  inches  in 
breadth.  This  has  also  been  called  a lobe,  Lobulus 
Quarlus  or  Anonymous , its  posterior  point  opposite 
the  papilla  of  the  lobulus  spigelii  forms  the  other 
porta  of  the  liver. 

The  peritoneum  is  extended  from  the  surface  of 
the  abdomen  to  the  surface  of  the  liver,  in  such  man- 
ner as  to  cover  it,  and  to  form  ligaments,  which  have 
a great  effect  in  retaining  it  in  its  proper  situation. 
The  whole  posterior  edge  of  the  liver  is  in  contact 
with  the  back  of  the  abdomen.  The  peritoneum 
above  the  liver  is  reflected  to  the  upper  surface  of  it, 
and  the  peritoneum  below  it  to  the  lower  surface  ; 
so  that  two  lamina  of  the  peritoneum  pass  from  the 
lower  part  of  the  diaphragm  at  the  back  of  the  abdo- 
men to  the  posterior  edge  of  the  liver.  These  pro- 
cesses of  the  peritoneum  are  considered  as  forming 
two  ligaments,  which  are  called  the  right  and  left 
lateral  ligaments.  A portion  of  the  posterior  surface 
of  the  liver,  uncovered  by  the  peritoneum,  is  often  in 
contact  with  a portion  of  the  tendon  of  the  diaphragm, 
also  uncovered  by  peritoneum  : around  this  place  of 
contact,  the  peritoneum  is  extended  from  the  dia- 
phragm to  the  liver,  and  thus  forms  what  has  been 
called  the  coronary  ligament  of  the  liver. 

The  peritoneum  of  the  right  side  of  the  diaphragm, 
and  of  the  abdominal  muscles,  as  far  down  as  the 


131 


Mode  of  supporting  the  Liver, 

umbilicus,  is  extended  to  the  liver,  and  joins  it  on 
the  convex  surface  immediately  opposite  to  the  um- 
bilical fissure.  The  peritoneum  from  the  left  side  of 
these  parts  does  the  same  j and  as  these  reflections 
©f  the  peritoneum  are  continued  from  so  low  a part 
as  the  umbilicus,  they  are  extended  not  only  to  the 
convex  surface  of  the  liver,  but  also  to  the  great 
notch,  and  along  the  umbilical  fissure. 

From  the  umbilicus  proceeds  a round  cord-like  lig- 
ament, which  in  the  foetal  state  was  a vein,  that 
passes  to  the  great  fissure  of  the  liver,  and  along  it. 
The  process  of  the  peritoneum  above  mentioned  is 
so  connected  with  this  cord,  that  it  encloses  it  in  its 
lower  edge,  and  the  whole  is  called  the  falciform 
ligament  of  the  liver.  The  cord,  when  named  se- 
parately, is  the  umbilical  or  the  round  ligament : and 
the  membrane  or  lamina  of  the  peritoneum  forms  the 
suspensory  ligament.  Besides  these,  the  peritoneum 
on  the  lower  side  of  the  liver  is  so  arranged,  that  it 
not  only  extends  to  the  stomach,  but  to  the  duodenum 
and  the  colon. 

By  these  ligaments  the  position  of  the  liver  must 
be  fixed  to  a great  degree ; and  there  is  one  additional 
connexion,  which  must  have  a great  effect  in  retain- 
ingit  in  its  proper  situation.  The  vena  cava  receives 
two  or  three  great  veins  from  the  liver,  at  the  place 
where  it  is  in  contact  with  the  posterior  edge  of  that 
viscus : these  veins  of  course  pass  directly  from  the 
substance  of  the  liver  into  the  cava,  and  connect  if  to 
that  vessel.  As  the  cava  is  supported  by  the  heart, 
and  also  by  the  diaphragm,  it  must  afford  a consider- 
able support  to  the  liver. 

When  the  stomach  and  intestines  are  distended, 
they  must  also  contribute  in  a considerable  degree  to 
the  support  of  the  liver. 

The  liver  has  a strong  tendency,  when  we  are 
erect,  to  change  its  situation  % and  some  considerable 


132  Acini  of  the  Liver. — Proper  Coat  of  the  Liver , 

support  is  necessary  to  counteract  this  tendency.  It 
would  move  to  the  right,  when  we  lie  on  the  right 
side,  if  it  were  not  in  contact  with  the  ribs  ; and  it 
inclines  to  the  left,  for  want  of  such  support,  when 
we  lie  on  the  left  side. 

It  has  been  computed,  that  the  liver  descends 
about  two  inches,  when  the  position  of  the  subject  is 
changed  from  the  horizontal  to  the  erect.  As  it  is 
in  contact  with  the  diaphragm,  it  is  obvious  that  it 
must  be  influenced  by  the  motions  of  that  muscle, 
and  that  it  must  descend  when  the  diaphragm  con- 
tracts. 

The  liver  is  composed  of  a substance  which  has 
some  firmness  of  consistence,  although  it  is  yielding; 
and  is  also  somewhat  brittle  or  friable.*  When  cut 
into,  the  sections  of  many  tubes,  or  vessels  of  dif- 
ferent diameters,  appear  on  the  cut  surface.  When 
the  texture  of  this  substance  is  more  closely  ex- 
amined, it  appears  somewhat  granulated,  or  com- 
posed of  very  small  bodies,  which  were  called  acini 
by  the  anatomists  who  first  described  them.  The 
whole  substance  is  enclosed  by  the  peritoneum,  which 
is  extended  to  it  from  the  surface  of  the  abdomen  in 
the  manner  that  has  been  already  described.  It  has 
also  a proper  coat  or  capsule  ; and  on  the  posterior 
edge,  where  the  lamina  of  the  lateral  ligaments  pass 
from  the  diaphragm  to  the  liver,  at  some  distance 
from  each  other,  a portion  of  the  liver,  covered  by 
this  coat  and  by  cellular  substance,  is  in  contact  with 
the  diaphragm.  The  same  thing  occurs  likewise  at 
the  coronary  ligament,  f 

The  liver  holds  the  first  place  among  the  glands 

* It  has  been  fractured  in  the  living  body  by  external  violence. 

f Many  anatomists  deny  the  existence  of  this  coat ; but  if  one  of  the 
lamina  of  the  ligaments  be  carefully  peeled  off  from  the  surface  of  a 
liver  which  is  slightly  affected  by  putrefaction,  it  will  be  apparent,  al- 
though very  thin.  It  was  described  by  M.  Laennec,  in  Le  Journal  de 
Medecine  for  1803. 


Vessels  of  the  Liver.-— Hepatic  Artery „ 133 

of  the  body  for  size,  but  it  is  still  more  remarkable 
for  some  other  circumstances  in  its  economy.  In 
addition  to  an  artery,  which  passes  to  it  as  arteries 
do  to  other  glands,  there  is  a large  vein  which  also 
enters  it  as  an  artery;  and  after  ramifying  through- 
out the  liver,  communicates,  as  does  the  artery,  with 
other  veins,  which  carry  the  blood  from  this  gland 
into  the  vena  cava  and  the  general  circulation. 
There  are  therefore  three  species  of  blood  vessels  in 
the  liver;  and  with  these  are  found  the  vessels  which 
carry  out  of  the  gland  the  fluid  secreted  by  it,  or  the 
bile. 

The  artery  of  the  liver  is  denominated  the  Hepa~ 
tic  Artery.  The  vein  which  goes  to  the  liver  is  call- 
ed the  Vena  Portarum , from  the  place  at  which  it 
enters.  The  veins  which  carry  to  the  vena  cava  the 
blood  brought  to  the  liver  by  the  hepatic  artery  and 
the  vena  portarum,  are  called  the  Hepatic  Veins ; 
and  the  duct  through  which  the  bile  flows  out  of  the 
liver,  is  called  the  Hepatic  Duct.  Three  of  these 
vessels,  the  Hepatic  Artery , the  Vena  Portarum , 
and  the  Hepatic  Duct , enter  the  liver  at  the  great 
fissure,  at  the  spot  where  the  prominences  exist  call- 
ed the  porta2 ; hence  the  name  vena  portarum  was 
applied  to  the  vein. 

These  vessels  ramify  in  the  manner  presently  to  be 
described;  and  it  is  ascertained  by  minute  anatomical 
investigation,  that  the  liver  is  entirely  composed  of  the 
ramifications  of  these  vessels  and  of  the  hepatic  veins, 
with  absorbent  vessels  and  nerves,  which  are  connect- 
ed together  by  cellular  membrane. 

It  has  been  already  observed,  that  the  first  great 
branch  sent  off  by  the  aorta  in  the  abdomen,  the  Cce- 
liac,  divides  into  three  branches,  which  go  respective- 
ly to  the  stomach,  the  liver,  and  the  spleen. 

The  Hepatic  is  generally  the  largest  of  these 
branches.  In  its  progress  towards  the  liver  it  sends 


134 


Vena  P or  forum - 


off  an  artery  to  the  stomach,  called  the  gastrica  dex- 
tra.  At  the  great  fissure  it  divides  into  two  branches"; 
the  right  branch,  which  supplies  the  right  lobe  of  the 
liver,  is  of  course  the  largest.  Tins  branch  sends  off 
oat  to  the  gall-bladder,  which  is  called  the  cystic  ar- 
tery ; and  also  some  smaller  branches : it  passes  un- 
der the  hepatic  duct,  and  ramifies  through  the  great 
lobe  of  the  liver.  The  left  branch  is  distributed 
through  the  left  lobe  of  the  viseus.  It  can  be  proved 
by  injection,  that  the  hepatic  artery  communicates  not 
only  with  the  hepatic  veins,  but  with  the  biliary  duct, 
and  the  vena  portarum  also.  It  has  been  disputed 
whether  the  size  of  this  artery  is  greater  than  would 
he  requisite  for  the  nourishment  and  animation  of  the 
liver- 

The  Vena  Portarum , the  great  peculiarity  of  the 
liver,  originates  from  all  the  chylopoietic  viscera  ex- 
cept the  liver,  and  is  of  course  formed  by  the  union 
of  the  veins  which  correspond  to  all  the  branches  of 
the  coeliae  and  mesenteric  arteries,  as  they  are  dis- 
tributed to  the  stomach  and  intestines,  the  spleen, 
the  pancreas,  and  the  omentum.  The  veins  from 
the  intestines  generally  form  two  great  trunks,  which 
are  denominated  the  greater  and  lesser  mesenteric 
veins.  The  great  mesenteric  vein  is  situated  to  the 
right,  and  rather  before  the  mesenteric  artery.— 
After  it  has  approached  the  origin  of  the  artery  it 
separates  from  it,  and  passes  behind  the  pancreas  i 
at  this  place,  nearly  in  front  of  the  spine,  it  is  joined 
by  the  great  vein  of  the  spleen,  which  forms  almost 
a right  angle  with  it,  and  these  constitute  the  great 
trunk  of  the  vena  portarum-  The  lesser  mesenteric 
vein,  which  corresponds  to  the  inferior  mesenteric 
artery,  and  brings  blood  from  the  pelvis  and  from 
the  left  part  of  the  colon,  becomes  finally  a large 
vessel,  and  commonly  unites  with  the  splenic  about 
an  inch  and  a half  before  its  junction  with  the  supe- 


135 


Vena  For iarum  . —Hepatic  Duct . 

sior  mesenteric  vein.  The  vena  portarum,  thus 
formed,  proceeds  towards  the  liver,  inclining  to  the 
right,  and  is  generally  about  three  inches  in  length: 
in  its  course  it  sometimes  receives  small  veins,  which 
in  other  cases  pass  to  its  splenic  and  mesenteric 
branches.  When  it  has  arrived  at  the  great  trans- 
verse  sinus  of  the  liver,  it  divides  into  two  large 
branches,  each  of  which  forms  nearly  a right  angle 
with  it.  Their  size  is  so  great,  that,  when  distend- 
ed with  injection,  they  appear  like  an  independent 
vessel,  into  which  the  vena  portarum  enters ; and  on 
this  account  they  are  called  the  great  Sinus  of  the 
vena  portarum.  They  do  not  adhere  firmly  to  the 
glandular  substance  of  the  liver,  but  are  united  to  it 
by  cellular  membrane.  The  right  branch  is  the 
widest  and  shortest.  It  generally  divides  into  three 
branches;  an  anterior,  a posterior,  and  a lateral 
branch;  which  ramify  minutely,  and  extend  them- 
selves in  the  right  lobe.  The  left  branch  is  much 
longer,  and  continues  to  the  extent  of  the  transverse 
fissure.  Near  its  termination  it  is  joined  by  the  urn- 
bilical  ligament,  which  has  been  already  mentioned. 
This  branch  is  generally  in  contact  with  a branch  of 
the  hepatic  artery  and  of  the  hepatic  duct ; and  ra- 
mifies, like  the  right  branch,  into  the  contiguous  parts 
of  the  liver. 

The  Hepatic  or  excretory  duct  originates,  by  very 
small  vessels,  from  the  acini  or  corpuscles  of  which 
the  liver  is  composed,  and  into  which  the  minute  ra- 
mifications of  the  vena  portarum  and  hepatic  artery 
extend.  They  accompany  these  vessels,  increasing 
as  they  increase,  although  the  fluid  they  contain  moves 
in  an  opposite  direction  ; and  two  large  branches 
which  they  ultimately  form  are  situated  at  the  portae 
of  the  liver,  in  contact  with  the  great  branches  of  the 
vena  portarum  and  the  hepatic  artery. 

These  three  vessels  are  in  contact  with  each  other 


136  Hepatic  Veins. — Nerves  of  the  Liver . 

before  they  enter  the  liver.  The  biliary  duct  is  an-^ 
terior,  the  vena  portarmn  posterior,  and  the  artery  to 
the  left  of  them.  They  are  accompanied  by  nerves 
and  lymphatic  vessels,  and  are  surrounded  by  a con-\ 
siderable  quantity  of  cellular  substance,  and  thus  ar- 
ranged are  partially  covered  with  peritoneum.  The 
cellular  substance  which  invests  them  continues  with 
them  into  the  liver,  and  is  more  particularly  con- 
nected with  the  vena  portarum.  It  is  called  Glis- 
son’s  Capsule,  and  was  supposed  to  have  some  con- 
tractile power,  which  assisted  the  circulation  of  the 
vena  portarum  ; but  that  idea  is  now  altogether  aban- 
doned, The  hepatic  veins,  which  receive  the  blood 
of  the  hepatic  artery  and  the  vena  portarum,  open 
into  the  anterior  part  of  the  vena  cava,  where  it  is 
in  contact  with  the  liver.  Generally  there  are  three 
of  these  veins,  but  sometimes  there  are  only  two ; 
in  which  case  one  of  them  is  formed  by  two  others, 
which  unite  immediately  before  they  open  into  the 
vena  cava.  It  is  to  be  observed,  that  the  various 
branches  of  these  veins  do  not  accompany  those 
branches  of  the  vena  portarum  or  hepatic  artery  to 
which  they  correspond,  but  form  very  large  angles 
with  them.  This  is  probably  owing  merely  to 
their  termination  in  a part  so  distant  from  that  in 
which  the  artery  and  the  vena  portarum  originate ; 
but  it  is  very  different  from  what  occurs  in  other 
glands. 

The  Nerves  of  the  Liver  are  derived  from  the 
sisnilunar  ganglions  of  the  splanchnic  nerves.  From 
these  many  nerves  proceed,  which  form  a net-work 
denominated  the  solar  plexus.  From  this  plexus 
many  threads  are  sent  off,  which  form  a net-work 
that  is  divided  into  the  right  and  left  hepatic  plexus. 
These  plexuses  surround  the  hepatic  artery  and  the 
vena  portarum,  and  accompany  them  in  their  ramifi- 
cations throughout  the  liver,  being  enclosed  by  Glis- 


Lymphatics . 137 

son's  capsule.  They  receive  some  threads  from  the 
stomachic  plexus,  formed  by  the  par  vagum.  A1- 
though  the  number  of  nervous  fibres  is  very  conside- 
rable, their  bulk,  compared  with  that  of  the  liver,  is 
very  small. 

The  Lymphatics  of  the  Liver  are  extremely  nu- 
merous; and  those  in  that  portion  of  the  peritoneum 
which  invests  the  liver  may  easily  be  rendered  con- 
spicuous : for  by  pressure  the  injected  fluid  can  be 
forced  from  the  trunks  and  large  branches  into  the 
smtll  ramifications,  in  opposition  to  the  valves.  When 
all  the  surface  is  injected  in  this  manner,  it  has  the 
colour  of  the  substance  injected;  as  is  the  case  with 
parts  which  are  very  vascular,  when  the  blood  ves- 
sels are  injected. 

The  deep-seated  lymphatics  are  also  very  numer- 
ous in  the  liver,  and  communicate  freely  with  the  su- 
perficial. 

The  superficial  lymphatics  which  are  on  the  upper 
surface,  proceed  through  the  diaphragm  into  the  tho- 
rax in  their  course  to  the  thoracic  duct.  Those  which 
are  deep-seated  emerge  from  the  liver  at  the  portae, 
where  the  great  vessels  enter,  and  unite  with  the  tho- 
racic duct  in  the  abdomen,  after  passing  through  se- 
veral glands.  The  lymphatics  of  the  lower  surface 
unite  with  the  deep-seated. 

The  glandular  or  parenchymatous  substance  of  the 
liver  is  of  a reddish-brown  colour,  and  moderately 
firm  consistence.  When  it  is  cut  into,  the  cut  surface 
exhibits  the  sections  of  the  branches  of  the  different 
blood  vessels  above  mentioned,  and  of  the  excretory 
ducts.  These  vessels  are  often  distinguishable  from 
each  other.  The  section  of  the  biliary  duct  appears 
the  thickest ; that  of  the  artery  next ; the  vena  por- 
tarum  is  next  in  order ; and,  last  of  all,  the  vense 
hepatic^o 

VOL.  n. 


18 


138  Glandular  Substance  of  the  Liver. 

The  branches  of  the  vena  portarum  are  surrounded 
by  cellular  substance,  or  Glisson’s  capsule ; and  there- 
fore adhere  less  to  the  substance  of  the  liver  than  the 
branches  of  the  hepatic  veins.  The  sections  of  the 
hepatic  ducts  have  often  bile  in  them,  and  are  there- 
fore termed  pori  biliarii.  The  branches  of  the  arte- 
ry are  also  very  distinguishable. 

When  the  internal  substance  of  the  liver  is  brought 
into  view,  and  examined  accurately,  it  appears  to  be 
formed  of  small  bodies,  or  acini,  which  are  distin- 
guishable from  each  other.  If  the  liver  happens  to 
be  torn  or  lacerated,  the  lacerated  surfaces  are  rough 
and  irregular,  owing  to  the  separation  of  these  acini 
from  each  other. 

It  is  asserted  by  several  microscopical  observers, 
that  a minute  branch  of  each  of  the  aforesaid  vessels 
can  be  traced  into  each  of  the  aeini.  It  is  also  de- 
clared, that  if  each  of  these  vessels  be  injected  sepa- 
rately with  mercury,  oil  of  turpentine  coloured,  or  a 
saturated  aqueous  solution  of  gutta  gamba,  there  is  no 
part  of  the  glandular  mass  as  large  as  a grain  of  mus- 
tard seed  in  which  these  vessels  will  not  be  found. 

Several  anatomists  of  the  first  character  have  like- 
wise declared,  that  a fluid  properly  injected  into  one 
of  these  vessels,  will  occasionally  pass  into  all  of 
them.  Thus  an  injection  will  not  only  pass  from  the 
vena  portarum  to  the  biliary  duct,  but  to  the  hepatic 
artery  and  veins  also.  It  will  likewise  pass,  in  a re- 
trograde course,  from  the  biliary  ducts  to  the  vena 
portarum,  and  to  the  hepatic  artery  and  the  hepatic 
veins ; or  from  any  one  of  the  four  orders  of  vessels 
into  the  three  others.* 

The  great  peculiarity  of  the  liver  is,  that  venous 
blood,  instead  of  arterial,  is  brought  to  it  for  the 
purpose  of  secretion.  Thus,  the  great  vein  of  the 

* I have  tried  the  experiment  and  find  the  assertion  to  be  correct— Ed. 


Peculiarity  of  the  Liver. — Gall  Bladder.  139 

ehylopoietic  viscera,  instead  of  passing  to  the  cava, 
enters  the  liver  by  the  transverse  fissure,  and  takes 
on  the  office  of  an  artery ; its  coats,  on  this  account, 
being  much  thicker  and  stronger  than  those  of  the 
hepatic  veins.* 

The  Biliary  or  Hepatic  Duct  is  formed  of  very 
minute  vessels,  which  originate  in  the  acini  above 
described ; these  unite  together  like  veins  until  they 
form  considerable  branches,  which  finally  compose 
the  great  ramifications  of  the  biliary  duct.  This 
duct  is  very  strong  and  firm,  and  on  its  internal  sur- 
face are  the  orifices  of  many  mucous  follicles  or 
ducts.  It  passes  from  the  transverse  fissure  of  the 
liver,  with  the  hepatic  artery,  as  before  described, 
and  at  the  distance  of  an  inch  and  a half  or  two 
inches  from  the  fissure,  it  unites  with  a duct  from  the 
gall  bladder,  which  is  called  the  Cystic  Duct.  This 
duct  is  nearly  equal  in  length  to  the  hepatic,  and  af- 
ter running  almost  parallel  to  it,  at  length  unites  so 
as  to  form  an  acute  angle  with  it.  The  cystic  duct 
is  smaller  than  the  hepatic,  and  they  unite  much  like 
two  branches  of  an  artery. 

The  Gall  Bladder , from  which  the  cystic  duct 
arises,  has  the  shape  of  a pear,  with  a very  long 
neck,  curved  in  a way  to  be  hereafter  described.  It 
is  situated  in  a superficial  pit  or  cavity  in  the  con- 
cave  surface  of  the  right  lobe  of  the  liver  ; and  its 
fundus,  or  basis,  often  projects  a small  distance  be- 
yond the  anterior  edge  of  the  viscus.  Its  position 
is  such,  that  it  extends  from  before  backwards,  and 
inclines  rather  to  the  left ; of  course,  therefore,  when 
the  subject  lies  on  his  back,  the  bottom  of  the  blad- 

* A case  is  related  by  Mr.  Abernethy,  in  the  London  Philosophical 
Transactions,  in  which  the  vena  portarum  terminated  in  the  vena  cava  be- 
low the  liver,  without  commmunicating  with  it.  The  hepatic  artery  was  the 
only  vessel  which  carried  blood  to  the  organ,  and  was  unusually  large;  the 
liver  being  nearly  of  the  natural  size.  Some  bile  was  in  the  gall  bladder, 
but  it  was  less  acrid  tha»  usual. 


140 


Gall  Bladder. 


der  is  the  uppermost  part  of  it ; when  he  lies  on  the 
left  side,  it  is  also  higher  than  the  neck ; and  when 
he  lies  on  the  right  side  it  is  the  lowermost. 

The  gall  bladder  consists  of  an  internal  coat,  and 
one  that  is  cellular  or  nervous,  and  has  somewhat  of 
a fibrous  appearance.  This  coat  connects  the  gall 
bladder  to  the  surface  of  the  pit  nr  cavity  in  which 
it  lies.  The  peritoneal  coat  of  the  liver  is  extended 
from  the  surface  of  the  viscus  over  that  part  of  the 
surface  of  the  gall  bladder  which  is  not  in  contact 
with  it. 

The  internal  coat  has  a peculiar  structure,  with  a 
faint  resemblance  to  that  of  the  villous  membrane. 
It  is  so  arranged  as  to  form  very  fine  folds,  which 
have  various  directions : in  some  places  they  make 
a net-work ; in  others,  as  the  neck  of  a bladder,  they 
are  longitudinal.  Many  mucous  follicles  exist  on  its 
internal  surface. 

The  neck  of  the  gall  bladder  is  suddenly  bent  down 
or  curved  upon  itself,  and  twisted,  so  that  it  resem- 
bles the  neck  of  the  swan,  when  the  head  of  that  bird 
is  applied  to  one  side  of  its  breast. 

A branch  of  the  hepatic  artery,  which  leaves  it  be- 
fore it  enters  the  liver,  is  appropriated  to  the  gall 
bladder,  and  is  therefore  denominated  the  cystic  artery. 
The  veins  corresponding  to  this  artery  empty  them- 
selves into  the  vena  portarum .*  The  lymphatic  ves- 
sels are  united  to  those  which  are  found  on  the  lower 
surface  of  the  liver,  and  the  nerves  are  derived  from 
the  hepatic  plexus. 

The  gall  bladder  appears  to  be  merely  a reservoir, 
into  which  bile  passes  through  its  duct  in  a retro- 
grade  direction.  If  air  be  blown  through  the  hepa- 
tic duct  from  the  liver,  it  will  pass  to  the  gall  blad- 
der almost  as  freely  as  it  passes  to  the  duodenum. 

* It  has  been  justly  observed  by  John  Bell,  that  the  veins  would  not  ter- 
minate thus,  if  bile  were  secreted  by  the  gall  bladder. 


Ductus  Communis  Choledochus.—  The  Bite . 141 

The  biliary  duct  from  the  liver,  after  receiving  the 
duct  from  the  gall  bladder,  takes  the  name  of  Ductus 
Communis  Choledochus.  It  is  wider  than  either  of 
the  other  ducts,  and  near  three  inches  in  length.  It 
passes  down  before  the  vena  portarum,  and  on  the 
right  of  the  hepatic  artery,  to  the  posterior  surface 
of  the  right  extremity  of  the  pancreas.  It  passes 
through  a small  portion  of  that  gland,  and  then  per- 
forates the  muscular  coat  of  the  duodenum  ; after 
which  it  proceeds  from  half  an  inch  to  an  inch  be- 
tween this  coat  and  the  villous,  and  opens  into  the 
cavity  of  the  intestine.  The  orifice  forms  a tubercle 
which  extends  lengthways  of  the  intestine,  and  is 
rounded  above  and  pointed  below,  with  a slit  in  it. 
While  this  duct  is  in  contact  with  the  pancreas,  a 
duct  from  that  gland  generally  opens  into  it,  so  that 
the  biliary  and  pancreatic  fluids  enter  the  duodenum 
by  the  same  orifice  ; but  sometimes  the  pancreatic 
duct  opens  into  the  duodenum,  by  a distinct  orifice, 
very  near  to  that  of  the  biliary  duct. 

The  Bile,  or  fluid  secreted  by  the  liver,  appears  to  an- 
swer a two-fold  purpose  in  the  animal  economy.  It 
produces  a chemical  effect  upon  the  alimentary  mix- 
ture which  passes  from  the  stomach  through  the  intes- 
tines ; and  it  increases  the  peristaltic  motion  of  those 
important  organs. 

By  an  inverted  action  of  the  duodenum,  some  of  this 
fluid  is  frequently  carried  upwards  into  the  stomach  : 
it  then  often  produces  only  slight  derangement  of  the 
functions  and  sensations  connected  with  that  viscous; 
but  sometimes  violent  vertigo,  and  even  convulsions , 
seem  to  have  arisen  merely  from  the  presence  of  a 
large  quantity  of  bile  in  the  stomach  : for  they  have 
gone  off  completely  upon  the  discharge  of  bile  by 
vomiting. 

Notwithstanding  these  effects  of  bile  in  certain 
cases,  in  which  a great  deal  of  it  exists  in  the  sto- 
mach, it  is  often  carried  into  the  mass  of  blood  in 
large  quantities,  and  appears  to  be  mixed  with  the 


142 


The  Pancreas. 


serum,  and  to  circulate  through  the  body,  without  pro- 
ducing any  very  sensible  effect  : thus  many  persons 
who  are  deeply  tinged  by  bile  in  their  blood,  experi- 
ence but  few  effects  that  can  be  imputed  to  the  mixture 
of  it  with  the  circulating  fluids : and  neither  the  brain 
nor  the  heart  appear  to  be  much  influenced  by  the  cir- 
cumstance. 

Bile  is  miscible  with  water  and  with  alcohol,  and 
also  with  oily  substances  ; and  it  often  assumes  a green 
colour,  when  mixed  with  acids.  The  colour  of  the 
alvine  discharges  is  derived  from  the  bile,  and  they 
are  therefore  sometimes  very  green,  when  the  acetous 
fermentation  takes  place  in  the  contents  of  the  sto- 
mach and  bowels. 

It  is  asserted  by  some  chemists,  that  ten  parts  in 
eleven  of  the  human  bile  consists  of  water  ; that  albu- 
minous matter  composes  about  one  forty-sixth  part  of 
it ; and  that  there  is  nearly  an  equal  quantity  of  re- 
sinous matter  in  it.  There  is  also  a small  quantity, 
(one  part  in  244,)  of  uncombined  soda  dissolved  in  it, 
and  a smaller  quantity  of  neutral  salts,  consisting  of 
soda  combined  with  the  phosphoric,  sulphuric  and  mu- 
riatic acids.  In  addition  to  these  is  a very  small 
quantity  of  phosphate  of  lime  and  of  oxide  of  iron, 
and  some  yellow  insoluble  matter. 

The  bile  in  the  Gall  Bladder  is  generally  more 
viscid  than  that  which  is  found  in  the  Hepatic  Duct . 

SECTION  II. 

Of  the  Pancreas. 

The  pancreas  is  a glandular  body,  which  has  a 
strong  resemblance  to  the  salivary  glands  in  seve- 
ral particulars.  It  is  seven  inches  in  length,  and 
is  irregularly  oblong  in  its  form,  one  extremity 
being  much  larger  than  the  other.  Its  large  extre- 
mity is  in  contact  with  the  duodenum,  and  it  ex- 
tends from  this  intestine  in  a transverse  direction  to 
the  spleen,  to  which  it  is  connected  by  the  omentum 
and  by  blood  vessels.  It  is  not  invested  by  the 
peritoneum,  but  is  situated  in  the  space  which  exists 


The  Pancreas . 


143 


between  the  two  lamina  of  the  mesocolon,  as  they 
proceed  from  the  back  of  the  abdomen,  before  they 
come  in  contact  with  each  other.  It  is  anterior  to 
the  aorta  and  vena  cava,  and  to  the  mesenteric  vein, 
or  main  branch  of  the  vena  portarum  ; being  connect- 
ed to  these  parts  by  cellular  membrane.  At  the  right 
extremity,  which  is  connected  with  the  duodenum,  is 
a process  of  the  gland  that  extends  downwards  in 
close  contact  with  the  intestine. — This  is  called  the 
head  of  the  pancreas,  or  the  lesser  prancreas. 

The  position  of  the  pancreas  is  such,  that  one  of 
its  surfaces  looks  forwards  and  rather  upwards,  and 
the  other  backwards  and  downwards ; one  edge  is 
of  course  posterior  and  superior,  and  the  other  ante- 
rior and  inferior.  The  posterior  of  these  edges  is 
much  thicker  than  the  other,  and  has  a groove  or 
excavation  which  is  occupied  by  the  splenic  blood 
vessels. 

This  gland  differs  from  the  other  large  glands  of 
the  abdomen,  inasmuch  as  it  has  not  a large  artery 
particularly  appropriated  to  it ; but  instead  of  this, 
it  receives  branches  from  the  contiguous  arteries. 

The  arterial  blood  of  this  gland  is  partly  supplied 
by  the  splenic  artery,  which,  in  its  course  from  the 
main  trunk  of  the  cceliac  to  the  spleen,  while  it  is  in 
the  groove  at  the  edge  of  the  pancreas,  sends  off  into 
the  gland  one  considerable  branch  called  the  great 
pancreatic,  and  a number  of  small  branches,  which 
go  off  in  succession.  In  addition  to  these,  the  pan- 
creas receives  vessels  from  one  of  the  branches  of 
the  hepatic  artery,  before  it  sends  off  its  great  rami- 
fications, as  well  as  small  twigs  from  several  other 
contiguous  arteries.  The  veins  correspond  with  the 
arteries,  but  ultimately  are  discharged  into  the  vena 
portarum. 

The  pancreas  resembles  the  salivary  glands  in 


144 


Pancreatic  Duct . 


colour,  and  also  in  texture ; for  it  it  of  a dull  white 
colour  with  a tinge  of  red,  and  it  appears  to  consist 
of  small  bodies  of  a granulated  form,  which  are  so 
arranged  as  to  compose  small  masses  or  lobes  that 
are  united  to  each  other  by  cellular  membrane. — , 
Each  of  these  granulated  bodies  receives  one  or 
more  small  arterial  twigs,  and  from  it  proceeds  not 
only  a vein  but  a small  excretory  duct,  which, 
uniting  with  similar  ducts  from  the  adjoining  granu- 
lated portions  or  acini,  forms  a larger  duct  in  each 
lobe  or  mass;  these  open  into  the  great  duct  of  the 
gland,  which  proceeds  through  it  lengthwise  from 
the  left  extremity,  in  which  it  commences,  to  the 
right. 

This  duet  is  situated  in  the  body  of  the  gland, 
which  must  be  dissected  to  bring  it  into  view.  It  is 
thin  and  transparent,  like  the  ducts  of  the  salivary 
glands,  and  is  rather  larger  in  diameter  than  a crow’s 
quill.  In  its  progress  towards  the  right  extremity 
of  the  gland  it  gradually  enlarges,  and  commonly 
receives  a branch  from  the  part  called  the  lesser 
pancreas.  It  most  commonly  unites  with  the  biliary 
duct  before  it  opens  into  the  duodenum  : sometimes 
these  ducts  open  separately,  but  very  near  to  each 
other.  They  penetrate  the  coats  of  the  intestine 
rather  obliquely,  and  between  four  and  five  inches 
from  the  pylorus.  This  canal  is  sometimes  called 
Dustus  Virsungii , after  an  anatomist  who  published 
a plate  of  it. 

The  pancreas  has  an  irregular  surface,  and  no  coat 
which  covers  it  uniformly.  It  is  invested  by  cellular 
membrane,  which  also  connects  its  different  lobes  to 
each  other.  Absorbent  vessels  and  nerves  are  traced 
into  it. 

The  portion  called  the  lesser  pancreas  adheres  to 
the  duodenum,  and  when  it  is  enlarged  by  disease., 


145 


Size  of  the  Spleen. 

the  passage  of  aliment  through  that  intestine  is  much 
impeded,  and  sometimes  completely  obstructed.* 

It  is  now  generally  believed  that  the  fluid  secreted 
by  the  pancreas  is  similar  to  that  which  is  produced 
by  the  salivary  glands. 

SECTION  III. 

Of  the  Spleen. 

The  Spleen  is  a flat  body  of  a bluish  colour,  and 
an  irregular  oblong  form,  with  thick  edges,  which  are 
indented  in  some  places. 

It  is  various  in  different  subjects,  both  in  size  and 
form.  Its  most  common  size  is  between  four  and  five 
inches  in  length,  and  about  three  or  four  inches  in 
breadth  ; but  it  has  often  been  found  of  more  than 
four  times  this  size ; and  it  has  also  been  seen  not 
much  longer  than  an  inch.  Its  ordinary  weight  is  be- 
tween six  and  nine  ounces ; but  it  has  varied  in  dif- 
ferent subjects  from  eleven  pounds  to  one  ounce.  It 
is  supposed,  by  many  physiologists,  that  it  frequent- 
ly varies  in  size  in  the  same  individual. 

It  is  situated  in  the  left  hypochondriac  region,  in 
contact  with  the  diaphragm,  below  the  eighth  rib. 
The  position  of  the  spleen  is  somewhat  oblique,— 
one  extremity  being  directed  downwards  and  rather 
forwards,  and  the  other  upwards  and  backwards ; 
but  when  the  stomach  is  distended,  the  lower  end  of 
it  is  pushed  forward  by  the  great  extremity  of  that 
viscus. 

In  general  it  is  so  deeply  seated  in  the  left  hypo- 

* In  several  cases  where  examination  after  death  evinced  that  the  pan- 
creas had  become  enlarged  and  indurated,  particularly  at  the  right  ex- 
tremity, the  principal  symptoms  wer e jaundice;  great  uneasiness  after  ta° 
ing  food;  vomiting  some  time  after  eating , but  not  immediately ; extreme 
acidity  of  the  matter  rejected 

Vol.  lie-  " 19 


146  Enlargement  of  the  Spleen 

chondriac  region,  that  it  is  out  of  view  when  the  sub- 
ject is  opened  in  the  ordinary  way  : but  in  some 
cases  of  enlargement,  after  the  intermitting  fever,  it 
has  extended  downwards,  nearly  as  low  as  the 
pelvis  ; and  towards  the  right  side  beyond  the  um- 
bilicus. 

The  external  surface  of  the  spleen  is  convex,  in 
conformity  to  the  surface  of  the  diaphragm,  with 
which  it  is  in  contact.  The  internal  surface  of  the 
spleen  is  irregularly  concave,  having  a longitudinal 
fissure  which  divides  it  into  two  portions. 

The  spleen  is  invested  by  the  peritoneum,  one 
process  of  which  is  often  extended  from  the  dia- 
phragm, above  and  behindit,  in  the  form  of  ligament. 
Another  process  of  the  same  membrane  is  extended 
to  it  from  the  great  extremity  of  the  stomach.  The 
peritoneum  is  also  continued  from  the  spleen  in  the 
form  of  omentum. 

Within  this  peritoneal  covering  is  the  proper  coat 
of  the  spleen,  which  is  so  closely  connected  to  it,  that 
many  anatomists  have  considered  them  as  one  mem- 
brane : they  are,  however,  very  distinct  at  the  great 
fissure,  but  the  external  coat  is  extremely  thin. 

The  proper  coat  of  the  spleen  is  not  very  thick  : 
it  is  dense  and  firm,  and  somewhat  elastic*  but  not 
much  so.  Iris  partly  transparent. 

The  spleen  has  a large  artery,  which  is  one  of  the 
three  great  branches  of  the  cceliac.  This  vessel  runs 
in  an  undulating  manner,  in  a groove  in  the  upper 
edge  of  the  pancreas,  and  in  this  course  sends  off 
many  small  branches  to  supply  that  gland.  The 
splenic  artery,  before  it  arrives  at  the  spleen,  divides 
into  five  or  six  branches,  which  are  also  undulating 
in  their  progress,  and  penetrate  into  the  body  of  the 
viscus  at  the  above  mentioned  fissure.  These  branches 
are  distributed  to  every  part  of  the  viscus,  and  ram- 
ify minutely. 


147 


Vessels  of  the  Spleen , 

From  these  branches,  or  from  the  main  trunk  be- 
fore it  ramifies,  three  or  four  smaller  branches  pro- 
ceed to  the  left  extremity  of  the  stomach.  They  are 
called  vasa  brevia  or  arterise  breves. 

The  arteries  which  enter  the  spleen  are  accom- 
panied by  veins  that  emerge  from  it,  and  unite  to 
form  a great  trunk.  This  trunk  observes  a course 
corresponding  to  that  of  the  splenic  artery,  and  re-  * 
ceives  veins  from  the  stomach  and  pancreas,  which  * 
correspond  with  the  arterial  branches  sent  to  those 
organs.  The  splenic  vein  is  one  of  the  principal 
branches  of  the  vena  portarum. 

The  splenic  artery  is  very  large  in  proportion  to 
the  viscus  to  which  it  is  sent,  and  the  vein  is  unusu- 
ally large  in  proportion  to  the  artery.  The  vein  is 
also  very  tender  and  delicate  in  its  structure. 

The  absorbent  vessels  of  the  spleen  are  very  nu- 
merous. It  has  been  asserted,  that  when  those  of 
the  external  coat  of  the  spleen  are  injected,  they  are 
sufficient  to  form  a fine  net-work  on  it.  The  absorb- 
ents of  the  deep-seated  parts  unite  to  the  superficial 
at  the*fissure  where  the  blood  vessels  enter.  They 
terminate  in  the  thoracic  duct,  after  passing  through 
several  lymphatic  glands. 

The  nerves  of  the  spleen  are  derived  from  the 
solar  .plexus  : they  form  a plexus  round  the  vessels 
and  accompany  them  through  the  viscus. 

The  spleen  consists  of  a substance  which  is  much 
softer  than  that  of  any  other  viscus  of  the  abdomen. 
This  substance  is  made  up  either  wholly  or  in  great 
part  of  the  ramifications  of  the  splenic  artery  and 
vein,  which  are  demonstrated  by  injections  to  be  very 
minute  and  numerous  in  this  body.  There  are  also 
many  fine  white  cords,  like  threads,  which  pass  from 
the  internal  surface  of  the  inner  coat  of  the  spleen 
into  its  soft  substance,  in  which  some  of  them  ramify. 
These  cords  connect  the  substance  of  the  spleen 


148  Malpighi  on  the  Structure  of  the  Spleen „ 

pretty  firmly  to  its  coat,  and  they  seem  to  have  the 
effect  of  rendering  the  exterior  part  of  the  substance 
more  firm  and  dense  than  the  internal.  They  are 
particularly  conspicuous  if  the  spleen  be  immersed 
in  water,  and  the  coat  pulled  off  while  it  is  in  that 
situation. 

The  spleen  has  a strong  resemblance  to  the  glan- 
dular organs,  but  has  no  excretory  duct,  and  its  par- 
ticular function  is  not  very  obvious  : for  these  reasons 
the  structure  of  this  organ  is  a subject  of  very  inte- 
resting inquiry. 

Malpighi,  who  took  the  lead  in  researches  of  this 
nature,  before  injections  of  the  blood  vessels  with 
wax  were  in  use,  after  investigating  the  structure  of 
the  spleen  by  long  maceration,  by  boiling,  by  infla- 
tion, by  the  injection  of  ink  or  coloured  fluids,  and 
by  examination  with  microscopes,  declared  that  its 
structure  was  cellular  ; that  the  cells  communicated 
more  freely  with  the  veins  than  the  arteries ; and 
that  they  might  be  considered  as  appendices  of  the 
veins.  He  also  asserted,  that  a large  number  of 
white  bodies  or  vesicles  were  to  be  found  in  those 
cells  and  throughout  the  whole  substance  of  the 
spleen,  which  were  in  bunches  like  grapes,  and  pre- 
served their  whitish  colour  although  the  vessels 
around  them  were  injected  with  a coloured  fluid. 
This  description  of  Malpighi  appears  to  have  been 
admitted  by  some  of  the  very  respectable  anatomists 
who  were  cotemporary  with  him  ; but  it  was  most 
zealously  opposed  by  Ruysch,  who  exhibited  the 
spleen  so  completely  injected  with  wax,  that  it  ap- 
peared to  be  composed  entirely  of  vessels.* 

Ruysch  appears  to  have  paid  great  attention  to 

* Two  plates,  taken  from  drawings  of  these  preparations,  are  published 
in  Ruysch’s  works.  One  is  attached  to  Epistola  Problematica  Quarta,  in 
the  second  volume ; and  the  other  to  Thesaurus  Septimus,  in  the  third 
volume. 


149 


De  La  Sone  on  the  Spleen „ 

this  subject,  and  to  have  made  many  preparations  of 
the  spleen.  From  these  he  derived  the  opinion,  that 
the  substance  of  this  organ  was  entirely  composed  of 
arteries,  veins,  absorbent  vessels  and  nerves ; and 
that  if  it  were  properly  injected  before  it  was  dis- 
sected, no  other  structure  would  be  found.  He 
stated,  that  the  minute  ramifications  of  the  blood 
vessels  appeared  to  have  acquired  a peculiar  quality, 
and  were  so  soft  and  delicate,  that  their  texture  was 
destroyed  by  the  least  friction ; and  that  by  the 
slightest  degree  of  putrefaction  they  appeared  to  be 
reduced  to  a fluid  state.  He  also  denied  the  exist- 
ence of  cells,  or  of  the  whitish  bodies  described  by 
Malpighi. 

The  question  thus  at  issue  between  these  great 
masters  of  their  art,  was  very  carefully  examined  by 
M.  De  La  Sone,  a French  physician,  whose  observa- 
tions are  published  in  the  Memoirs  of  the  Academy 
of  Sciences  for  1754.  After  repeating  the  proces- 
ses of  each  of  these  anatomists,  and  instituting  some 
others  in  addition,  he  adopted  the  opinion  that  there 
was  in  the  texture  of  the  spleen  a pulpy  substance 
which  was  not  a mere  coagulum,  but  which,  howev- 
er, could  not  be  injected. 

He  derived  his  opinion  from  this  fact  among  others. 
After  macerating  the  spleen  a considerable  time,  and 
injecting  water  into  the  vessels  until  it  returned  co- 
lourless, he  injected  ink,  and  confined  it  some  time  in 
the  vessels  by  tying  them : he  then  allowed  the  ink 
to  flow  out  of  the  vessels,  and  made  various  sections 
of  the  spleen,  but  no  ink  appeared  in  the  pulpy  sub- 
stance, although  it  was  visible  in  many  small  vessels 
which  ramified  in  that  substance.  He  observes  that 
this  could  not  have  been  the  case,  if  the  pulpy  sub- 
stance had  been  composed  entirely  of  vessels,  as  was 
supposed  by  Ruyseh. 

He  also  examined  the  spleen  after  it  had  been  in- 


150  Haller  and  the  French  Anatomists  on  the  Spleen . 

jected  with  wax,  according. to  the  manner  of  Ruyseh, 
and  believed  not  only  that  the  pulpy  matter  remain- 
ed uninjected,  but  that  Ruyseh  himself,  in  his  own 
preparations,  removed  this  substance,  supposing  it  to 
exist  for  the  mere  purpose  of  connecting  the  vessels 
to  each  other. 

To  see  the  blood  vessels  in  the  same  state  of  de- 
tention in  which  they  were  during  life,  he  tied  the 
splenic  vessels  in  a living  animal,  and  removed  the 
spleen  with  the  ligatures  on  the  vessels.  In  this 
situation  he  boiled  it,  and  then  examined  the  ap- 
pearance of  the  vessels  and  the  pulpy  substance. — 
From  these,  as  well  as  his  other  observations,  he 
decided,  that  the  pulpy  substance  did  not  consist  en- 
tirely of  vessels,  but  was  an  additional  and  different 
structure. 

He  also  suggested,  that  as  the  brain  and  the  mus- 
cular fibres  were  so  covered  by  blood  vessels  in  the 
injected  preparations  of  Ruyseh,  that  they  appeared 
to  be  composed  entirely  of  vessels,  when  in  fact  they 
consisted  of  a different  substance,  so  the  pulpy  sub- 
stance of  the  spleen  was  covered  ar  obscured  by  the 
blood  vessels  which  passed  through  it,  without  con- 
stituting its  whole  substance. 

He  confirms  the  account  of  Malpighi  respecting  the 
Whitish  Vesicles  or  Follicles  ; and  states,  that,  in  a 
majority  of  cases  they  are  not  to  be  discovered  with- 
out a particular  preparation  ; but  that  they  are  gene- 
rally made  obvious  by  long  maceration  of  the  spleen 
in  water.  In  his  opinion  they  are  the  most  essential 
part  of  the  organ. 

Notwithstanding  these  investigations  of  M.  De  La 
Sone,  the  question  respecting  the  structure  of  the 
spleen  remains  not  completely  decided  even  to  this 
day. 

Haller,  who  was  perfectly  well  acquainted  with 
the  subject,  inclined  to  the  opinion  of  Ruyseh ; 


151 


British  Anatomists  on  the  Spleen, 

while  Sabatier  adopted  completely  the  opinion  of  De 
La  Sone; 

It  appears  from  the  statement  of  Gavard,  that  De- 
sault did  not  admit  the  existence  of  the  transparent 
bodies;  although  he  believed  that  the  pulpy  substance 
of  the  spleen,  consisted  of  cells  which  resembled 
those  of  the  cavernous  bodies  of  the  penis. 

Boyer,  whose  descriptions  of  the  animal  structure 
appear  to  have  been  formed  with  scrupulous  exacti- 
tude, admits  the  existence  of  transparent  bodies; 
sometimes  so  small  as  to  be  scarcely  visible,  and 
sometimes  as  large  as  the  head  of  a pin.’  He  ob- 
serves, that  the  best  method  of  examining  them  is  to 
place  a very  thin  slice  of  the  spleen  between  the  eye 
and  a strong  light,  when  the  transparency  of  these 
bodies  occasions  the  slice  of  the  spleen  to  appear  as 
if  perforated. 

As  to  the  general  structure  of  the  pulpy  substance, 
he  avows  himself  unable  to  decide  respecting  if;  but 
observes,  that  upon  examining  the  cut  surface  of  the 
spleen,  you  perceive  black  liquid  blood  flow  from 
the  vessels ; if  you  then  scrape  this  surface,  you  may 
express  easily  a species  of  sanies  different  from  that 
which  flows  from  the  vessels,  which,  after  exposure, 
becomes  red,  and  resembles  coagulated  blood  ; whe- 
ther this  is  contained  in  the  capillary  vessels,  or  in 
the  cavities  of  this  organ,  he  acknowledges  himself 
unable  to  determine. 

Notwithstanding  the  sentiments  of  these  French 
gentlemen,  many  of  the  British  Anatoihists,  who  are 
entitled  to  great  attention  on  account  of  their  skill  in 
minute  injections,  have  adopted  the  ideas  of  Ruysch. 
Among  these  are  to  be  mentioned  the  late  Dr.  F, 
Nicholls,  and  many  of-  the  anatomists  of  London,  as 
well  as  the  second  Professor  Monro,  of  Edinburgh. 
There  are,  however,  two  remarkable  exceptions  to 
this  account  of  the  British  anatomists*  The  late 


152  British  Anatomists  on  the  Spleen* 

Mr.  Faleonar,  who  wrote  a dissertation  on  the  situa- 
tion and  structure  of  the  spleen,  which  contains  the 
sentiments  of  the  late  truly  respectable  Mr.  Hewsoq,* 
after  stating  that  the  organ  was  extremely  vascular, 
so  that  when  injected  it  appeared  like  a mere  conge- 
ries of  vessels,  makes  this  unequivocal  assertion — 
that  there  are  innumerable  cells  dispersed  through- 
out the  whole  substance  of  it,  which  are  so  small  that 
they  are  only  to  be  discovered  by  the  aid  of  a micro - 
scope  ; and  are  to  be  seen  after  steeping  a thin  piece 
of  spleen,  the  blood  vessels  of  which  have  been  mi- 
nutely injected,  in  clear  water  during  a day,  and 
changing  the  water  frequently.  He  also  adds,  that 
the  ultimate  branches  of  the  arteries  and  veins  form  a 
beautiful  net-work  on  each  cell ; and  that  these  cells 
are  sufficiently  distinguished  from  the  irregular  inter- 
stices of  the  cellular  substance,  by  their  round  figure 
and  their  great  regularity. 

Mr.  Everard  Home,  in  his  papers  on  the  structure 
and  uses  of  the  spleen,  confirms  the  account  of  the  ve- 
sicles in  this  organ ; and  adds  that  these  vesicles  are 
occasionally  seen  in  a distended  and  in  a contracted 
state.  That  when  distended  they  are  twice  as  large 
as  when  contracted,  and  are  distinguishable  by  the 
naked  eye  ; whereas,  when  contracted,  they  require 
a magnifying  glass  to  be  distinctly  seen.  These  ob- 
servations appear  to  have  been  made  upon  quadru- 
peds.! 

Professor  Soemmering  appears  to  unite  in  the  ge~ 
neral  sentiment  of  the  British  anatomists,  that  the 
spleen  is  simply  vascular.  He  says,  that  the  tuber- 
culi  which  sometimes  appear  in  it,  when  examined 
with  a magnifying  glass  appear  to  be  composed  en- 
tirely of  vessels. 

* See  Experimental  Inquiries,  voi.  iii. 

f See  the  London  Philosophical  Transactions  for  1808. 


Questions  relating  to  the  Structure  of  the  Spleen.  153 

There  are  therefore  two  questions  not  perfectly  de- 
cided respecting  the  spleen. 

First.  Whether  its  general  structure  is  simply  vas- 
cular, or  whether  there  is  any  other  structure  either 
cellular  or  more  substantial,  which  composes  its  ge- 
neral bulk. 

Second.  Whether  the  small  transparent  vesicles, 
originally  described  hy  Malpighi,  are  to  be  regarded 
as  essential  parts  of  the  structure  of  the  spleen. 

With  respect  to  the  first  question,  the  injections  of 
Ruysch,  and  of  the  British  Anatomists  in  general, 
and  even  of  Mr.  Hewson,  as  well  as  of  Haller  and 
Soemmering,  seem  to  afford  positive  facts  in  opposi- 
tion to  those  of  a negative  kind  adduced  by  M.  De 
La  Sorie,  and  render  it  highly  probable  that  the  ge- 
neral structure  is  simply  vascular. 

But  the  second  question  stands  on  differentgrounds* 
The  existence  of  small  transparent  vesicles,  although 
denied  by  Ruysch,  and  neglected  by  the  British  Ana- 
tomists in  general,  was  asserted  as  a positive  fact  by 
Malpighi  and  De  La  Sone  ; and  their  assertions  have 
been  confirmed,  not  only  by  most  of  the  French  Ana- 
tomists, but  also  by  Hewson  and  Home  among  the 
British. 

The  sentiments  of  physiologists  respecting  the  func- 
tions of  the  spleen,  are  more  discordant  than  those  of 
anatomists  respecting  its  structure  ; although  the  sub- 
ject has  been  considered  by  many  authors  of  great  in- 
genuity.^ 

* See  M.  Lieutaud.  Elementa  Physiologic?, 

Hewson’s  Experimental  Inquiries, 'vol.  iii. 

Dr.  Rush.  Medical  Museum,  vol.  iii.' 

Haller.  Elementa  Pbysiologis,  tom.  vi.  page'414. 


Yol,  n» 


20 


CHAPTER  IV* 

OF  THE  URINARY  ORGANS  AND  THE  GLANDULE 
RENALES. 

The  urinary  organs  consist  of  the  Kidneys,  which 
are  situated  in  the  lumbar  regions ; of  the  Bladder, 
which  is  in  the  pelvis ; of  the  Ureters,  which  are 
flexible  tubes  or  canals  that  pass  from  the  kidneys  to 
the  bladder;  and  of  the  Urethra,  or  tube  through 
which  the  urine  is  discharged  from  the  bladder. 

These  organs  have  but  little  connexion  with  the 
peritoneum.  The  kidneys  are  behind  it ; and  a con- 
siderable quantity  of  cellular  membrane  is  placed 
between  them  and  it.  The  ureters  are  also  behind  it; 
and  but  a part  of  the  bladder  is  invested  with  it. 

The  Glandulx  Benales  are  described  with  the  uri- 
nary organs,  on  account  of  their  contiguity  to'the  kid- 
neys : and  to  avoid  a derangement  of  the  natural  or- 
der of  description  they  are  considered  first. 

The  urethra  pertains  to  the  organs  of  generation 
as  well  as  to  the  urinary  organs,  and  can  be  descri- 
bed most  advantageously  with  them. 

SECTION  I. 

Of  the  Glandulx  Benales . 

These  are  two  small  bodies,  situated  on  the  psoas 
muscles,  one  on  each  side  of  the  spine,  behind  the 
peritoneum  and  above  the  kidney,  being  in  contact 
with  its  upper  and  anterior  edge.  They  have  an  ir- 
regular semilunar  figure  with  three  sides,  one  of 


The  Kidneys  and  Ureters . 155 

which  is  accommodated  to  the  convexity  of  the  kid- 
ney.  Their  colour  is  commonly  a dull  yellow. 

The  appearance  and  texture  of  these  bodies  have 
some  resemblance  to  those  of  glands,  and  hence  their 
name,  but  they  have  no  excretory  duct. 

When  they  are  laid  open  by  an  incision,  a cavity 
often  appears,  which  is  somewhat  triangular,  and 
from  the  lower  part  of  it  a small  thin  ridge  arises.^ 

A small  quantity  of  fluid  is  generally  found  in  it, 
which  has  a very  dark  colour  in  adults,  is  yellowish 
in  young  subjects,  and  red  in  infants. 

These  bodies  have  not  a single  artery  appropriated 
to  them,  as  the  spleen  has,  but  receive  small  branches 
from  several  contiguous  sources  ; viz.  from  the  arte- 
ries of  the  diaphragm,  from  the  coeliac  artery  or  the 
aorta,  and  from  the  arteries  of  the  kidneys.  There 
is  generally  one  principal  vein,  as  well  as  some 
that  are  smaller,  belonging  to  each  of  these  bodies : 
the  large  vein  on  the  right  side  generally  opens  into 
the  vena  cava,  and  on  the  left  into  the  left  eraulgent 
vein. 

These  bodies  were  first  described  by  Eustachius, 
and  have  been  regarded  with  attention  by  many  ana- 
tomists since  that  period.  They  exist  in  a great  num- 
ber of  animals ; but  their  nature  and  functions  are 
altogether  unknown. 

SECTION  II. 

Of  the  Kidneys  and  Ureters. 

The  kidneys  are  two  glandular  bodies  which  se- 
crete the  urine.  They  are  of  a dull  red  colour,  and 
their  form  has  a strong  resemblance  to  that  of  the 
bean  which  bears  their  name.  They  have  a peeu- 

* The  cavity  in  these  bodies  has  sometimes  been  sought  for  in  vain. 
Haller  found  it  in  sixteen  cases  out  of  nineteen. 


156 


The  Kidneys . ' 

liar  texture,  which  is  uniform,  and  not  granulated 
or  composed  of  acini ; and  they  are  covered  by  a thin 
delicate  tunic,  which  has  no  connexion  with  the  pe- 
ritoneum. 

They  are  situated  in  the  lumbar  regions  of  the  ab- 
domen, one  on  each  side  of  the  spine.  They  are 
opposite  to  the  two  last  dorsal  and  the  two  first  lum- 
bar vertebrae.  They  rest  principally  upon  the  psoas 
and  quadratus  lumborum  muscles,  and  their  posi- 
tion is  oblique  ; the  concave  edge  presenting  inwards 
and  forwards,  the  convex  edge  backwards,  and  the 
upper  extremity  approaching  nearer  to  the  spine  than 
the  lower. 

The  Right  Kidney  is  situated  rather  low'er  than 
the  left : it  is  below  the  posterior  part  of  the  right 
lobe  of  the  liver,  and  behind  the  duodenum  and  the 
colon.  The  Left  Kidney  is  below  the  spleen,  and 
behind  the  descending  portion  of  the  colon.  Each 
of  the  kidneys  is  below'  and  very  near  to  one  of  the 
glandulae  renales. 

They  are  surrounded  with  a large  quantity  of  lax 
adipose  membrane,  which  in  corpulent  persons  forms 
a very  large  mass  of  adeps  around  them  ; while  in 
the  emaciated  they  are  surrounded  with  a membrane 
almost  free  from  fat.  Each  kidney  has  two  broad 
sides,  two  extremities,  and  two  edges.  The  side  or 
surface  which  is  posterior,  when  the  kidney  is  in  its 
natural  situation,  is  rather  broader  than  the  other. 
The  upper  extremity,  or  portion,  is  also  broader 
and  larger  than  the  lower.  The  edge  which  is  pos- 
terior and  external  is  regularly  convex  ; the  anterior 
edge  is  concave ; but  the  concave  edge,  or  margin, 
is  not  very  regular.  In  the  middle  it  is  largely  in- 
dented ; in  this  indentation  is  a deep  fissure,  which 
separates  the  two  broad  surfaces  or  sides  of  the 
gland  from  each  other;  and  here  the  breadth  of  the 
posterior  surface  is  evidently  greater  than  the  anterior. 


157 


. The  Kidneys. 

Each  of  the  kidneys  receives  a large  artery,  which 
proceeds  immediately  from  the  aorta,  nearly  in  a 
rectangular  direction.  A vein,  which  opens  into  the 
vena  cava,  accompanies  the  artery.  It  is  obvious, 
from  the  situation  of  the  kidneys  with  respect  to  the 
great  vessels,  that  the  artery  on  the  right  side  must 
be  longer  than  that  on  the  left,  and  that  the  reverse 
of  this  must  be  the  case  with  the  veins;  the  veins  are 
also  anterior  to  the  arteries.  At  the  great  fissure  these 
vessels  divide  into  several  branches,  wThich  enter  the 
kidney  at  that  place.  The  branches  of  the  vein  are 
before  and  above ; those  of  the  artery  are  below,  and 
in  the  middle.  Surrounded  more  or  less  by  the 
branches  of  those  vessels,  is  a membranous  sac,  the 
breadth  of  which  extends  from  above  downwards. 
This  sac  terminates  in  a tube  that  proceeds  from  the 
lower  part  of  the  fissure  down  to  the  bladder.  The 
sac  is  denominated  the  pelvis  of  the  kidney,  and  the 
tube  a ureter:  each  of  these  parts  will  soon  be  more 
particularly  described. 

The  substance  of  the  kidney,  as  has  been  already 
said,  is  uniform  in  its  texture,  and  of  a reddish  brown 
colour.  When  it  is  divided  by  an  incision  made 
lengthways,  and  from  its  convex  to  its  concave  edge, 
there  appears  to  be  a small  difference  in  the  different 
parts  of  it.  The  exterior  part,  which  is  called  corti- 
cal, is  rather  more  pale  in  colour  and  softer  in  con- 
sistence than  the  internal  part.  It  varies  in  thickness, 
so  that  some  writers  have  described  it  as  equal  to  two 
lines,  and  others  to  one-third  of  the  kidney.  In  a 
majority  of  subjects  it  will  be.  found  between  the  two 
statements. 

The  interior  part  is  called  medullary7,  or  tubular, 
and  appears  to  be  composed  of  very  fine  tubes. 
These  tubes  are  so  arranged,  that  a number  of  pa- 
pillae or  cones  are  formed  by  their  convergence,  and 
project  into  the  fissure  of  the  kidney.  These  pa- 


158 


The  Kidneys . 4 

pillae  have  been  supposed  to  consist  of  a substance 
different  from  either  of  the  two  above  mentioned, 
but  they  appear  to  be  formed  merely  by  the  tubular 
part. 

The  arteries,  accompanied  by  corresponding  veins, 
and  by  nerves  and  absorbent  vessels,  after  ramifying 
in  the  fissure  of  the  kidney,  proceed  into  its  substance, 
and  continue  their  aborescent  ramifications  until  they 
have  arrived  very  near  the  exterior  surface.  They 
are  so  uniformly  distributed  to  the  different  parts  of 
the  organ,  that  when  the  blood  vessels  are  injected 
with  wax,  and  the  substance  of  the  kidney  is  removed 
from  the  injected  matter,  as  is  the  case  in  corroded 
preparations,  the  injection  exhibits  accurately  the 
form  of  the  kidney. 

The  large  branches  of  the  blood  vessels  occupy 
the  vacuities  between  the  papillae  in  the  fissure  of 
the  kidney.  When  they  penetrate  the  substance  of 
the  kidney,  they  are  enclosed  by  sheaths  which  are 
derived  from  the  cqat  of  the  gland,  and  are  sur- 
rounded by  membrane,  which  frequently  contains 
adeps. 

There  are  commonly  ten  or  twelve  papillae  in  the 
fissure  of  each  kidney,  but  there  are  sometimes  more 
and  sometimes  less  than  this  number.  These  pa- 
pillae are  surrounded  by  a membranous  sac  of  a cor- 
responding form  ; the  papilla  being  a cone,  and  the 
sac  resembling  the  upper  part  of  a funnel.  The 
sac  is  therefore  called  an  infundibulum,  or  calyx. 
Sometimes  there  are  two  papillae  in  each  infundibu- 
lum, and  then  the  form  of  the  sac  is  not  so  regular. 
The  infundibulum  adheres  to  the  base  of  the  papilla, 
but  lies  loose  about  the  other  parts  of  it.  Each  in- 
fundibulum communicates,  at  its  apex,  with  the  pel- 
vis of  the  kidney. 

The  Pelvis,  as  has  been  already  mentioned,  is  a 
membranous  sac  which  terminates  in  the  ureter,  ex- 


Cortical  and  Tubular  Portions  of  the  Kidney . 159 

terior  to  the  kidney.  This  sac  generally  divides  it- 
self, in  the  fissure  of  the  kidney,  into  three  large  ir- 
regular branches,  each  of  which  very  soon  terminates 
in  three  or  four  of  the  infundibula  above  described. 
That  portion  of  the  sac  which  terminates  in  the  ure- 
ter is  exterior  to  the  kidney. 

When  the  interior  parts  of  the  kidney  are  exposed, 
to  view,  by  the  section  above  mentioned,  after  the 
arteries  and  veins  have  been  minutely  injected,  the 
cortical  part  will  be  found  to  consist  almost  entirely 
of  the  minute  ramifications  of  these  vessels.  Among 
them  are.  some  small  bodies,  which  are  dispersed 
through  the  substance,  like  berries  on  a bush : these 
are  asserted  also  to  be  composed  of  vessels. 

The  tubular  part  certainly  proceeds  from  this  vas- 
cular cortical  substance  : for  Ruysch,  and  after  him 
several  other  injectors,  have  filled  these  tubes  with 
injection  thrown  into  the  arteries. 

The  tubuli,  of  which  this  part  is  composed,  seem 
to  arise  obscurely  from  the  cortical  part.  They  soon 
assume  somewhat  of  a radiated  direction,  and  are 
finally  arranged  so  as  to  form  the  papillae  or,  cones 
above  described. 

On  these  papilla  or  cones  some  of  them  can  be 
traced,  uniting  with  each  other,  to  form  larger  tubes, 
which  terminate  on  the  surfaces  of  the  papillae,  in 
orifices  large  enough  to  be  seen  distinctly.  From 
these  orifices  urine  may  be  forced  out  by  compress- 
ing the  papillae.  On  this  account  the  tubes  have  been 
called  tubuli  uriniferi.  , 

In  the  foetal  state  the  kidney  is  formed  of  a num- 
ber of  distinct  lobuli,  each  of  which  consists  of  a 
papillae  with  the  cortical  matter  connected  to  its 
base.  Soon  after  birth  these  lobuli  coalesce  ; and 
in  two  or  three  years  the  substance  of  the  kidney 
appears  uniform,  as  above  described.  In  some  ani- 
mals this  lobulated  structure  continues  during  life  ; 


160  Nerves  and  Lymphatics.— Coat  of  the  Kidney. 

in  them,  and  also  in  the  foetus,  each  lobe  appears 
like  a distinct  organ.  Although  in  the  adult  kidney 
this  structure  has  disappeared,  the  papillae  and  the 
tubular  part  connected  with  them  are  somewhat  de- 
tached from  each  other,  in  a manner  corresponding 
to  their  original  arrangement.  . 

The  Nerves  of  the  Kidneys  originate  from  the  se- 
milunar ganglion,  formerly  mentioned.  They  form 
a plexus  round  the  blood  vessels,  and  go  with  them 
into  the  gland. 

The  kidneys  have  internal  and  external  absorbent 
vessels,  although  the  external  vessels  are  very  small. 
These  absorbents  pass  through  glands  in  the  lum- 
bar region  to  the  thoracic  duct. 

The  proper  coat  of  the  kidney  is  said,  by  some 
anatomists,  to  consist  of  two  lamina  ; but  this  can- 
not be  shown  in  common  cases.  It  appears  simple 
in  its  structure,  and  very  flexible.  It  is  but  slightly, 
connected  to  the  glandular  substance  which  it  en- 
closes, and  may  be  easily  peeled  off.  It  is  reflected 
inwards  at  the  fissure  of  the  kidney,  and  can  be 
traced  inwardly  to  some  distance,  forming  sheaths 
for  the  vessels.  In  this  internal  situation  it  is  very 
thin. 

The  Ureters. 

The  pelvis  of  the  kidney  terminates  exteriorly  in 
the  Ureter , which  is  a membranous  cylindrical  tube, 
rather  flattened,  and  between  three  and  five  lines  in 
diameter,  with  some  variations  in  this  respect. 

The  Ureters  descend  from  the  pelvis  of  the  kid- 
ney so  as  to  pass  obliquely  across  the  psoas  muscle 
and  the  great  iliac  vessels.  They  are  behind  the 
peritoneum,  but  in  contact  with  it.  They  approach 
the  pelvis  near  the  junction  of  the  os  ilium  with  the 
sacrum,  and  thence  descend  forwards  and  inwards, 
surrounded  with  loose  cellular  membrane,  to  the 


Structure  of  the  Ureters.  161 

lower  part  of  the  bladder,  into  which  they  are  in- 
serted at  its  external  and  posterior  part.  They  first 
penetrate  obliquely  the  muscular  coat,  and  then  pro- 
ceed between  the  muscular  and  internal  coats,  from 
half  an  inch  to  an  inch,  in  an  oblique  direction,  from 
without  inwards  and  forwards,  when  they  terminate 
by  small  orifices  in  the  internal  coat,  each  of  which 
is  at  an  equal  distance,  (rather  more  than  an  inch,) 
from  the  orifice  of  the  urethra,  thus  forming  a triangle 
with  it. 

The  ureters  are  said  to  have  three  coats.  The  ex- 
terior appear  to  be  derived  from  the  cellular  sub- 
stance : within  it  is  another,  which  has  been  regarded 
very  differently  by  different  anatomists  ; some  consi- 
dering it  as  merely  membranous,  and  others  as  mus- 
cular. If  the  ureter  be  laid  open  and  the  internal 
coat  peeled  off,  the  muscular  structure  of  this  coat  is 
often  very  perceptible. 

The  internal  coat  is  called  villous,  or  mucous,  and 
is  continued  from  the  internal  coat  of  the  bladder. 
Over  this  coat  mucous  is  constantly  spread,  which 
defends  it  from  the  acrimony  of  the  urine.  It  is 
very  difficult  to  separate  the  two  last  mentioned  coats 
from  each  other. 

The  ureters  receive  blood  vessels  and  nerves  from 
those  of  the  neighbouring  parts.  Their  internal 
coat  is  very  vascular,  and  is  also  very  sensible  of  ir- 
ritation. The  passage  of  a small  urinary  calculus 
can  be  traced  from  the  pelvis  of  the  kidney  to  the 
bladder,  by  the  exquisite  pain  and  the  spasmodic  af- 
fections which  it  often  excites. 


Vol,  II. 


21 


162 


Situation  of  the  Bladder . 


SECTION  III. 

Of  the  Urinary  Bladder. 

The  urinary  bladder  is  a large  sac,  of  a muscular 
and  membranous  structure,  which  occupies  the  ante- 
rior part  of  the  cavity  of  the  pelvis,  immediately 
within  the  ossa  pubis. 

The  size  of  the  bladder  is  in  a continued  state  of 
variation,  according  to  the  quantity  of  urine  secreted. 
When  moderately  distended,  it  is  of  an  irregular 
oval  form,  but  rather  more  flat  at  its  lower  extremity 
than  above.  It  varies  in  form  according  to  the  dif- 
ferent circumstances  of  the  pelvis  to  which  it  has  been 
subjected. 

It  is  fixed  firmly  and  immoveably  to  the  pelvis 
immediately  within  the  symphysis  pubis  ; so  that  it 
is  always  to  be  found  there  of  a larger  or  smaller 
size.  This  fixture  is  produced  by  the  attachment  of 
the  lower  portion  of  fundus  of  the  bladder  to  the 
parts  beneath  it,  but  principally  by  the  anterior  liga- 
ments of  the  bladder  which  proceed  one  on  each  side 
from  the  lateral  surfaces  of  the  prostate  gland,  and  are 
inserted  into  the  pubis  of  the  corresponding  side  at 
the  lower  part  of  the  symphysis.  These  ligaments 
are  in  fact  the  extension  of  a membrane,  (called  by 
the  French  Anatomists,  the  pelvic  aponeurosis,)  which 
proceeds  from  the  upper  part  of  the  pelvis  to  the 
side  of  the  prostate  gland  and  bladder,  and  which 
may  be  seen  by  turning  off  the  peritoneum  from  the 
levator  ani  muscle.*  It  is  sometimes  completely 
empty,  and  occupies  no  more  space  than  the  thickness 

* See  Thesis  on  Femoral  Hernia,  &c.  by  Gilbert  Breschet.  Paris,  April, 
1819.  Colies’  Surgical  Anatomy,  Dublin,  1811,  for  a more  minute  account 
of  this  membrane.  Ed-. 


163 


Situation  of  the  Bladder. 

of  its  coats  requires.  When  moderately  distended, 
it  occupies  a considerable  portion  of  the  pelvis  : 
when  distention  increases,  it  presses  the  parts  poste- 
rior to  it  against  the  sacrum,  and  extends  itself  above 
the  brim  of  the  pelvis  into  the  general  cavity,  rising 
not  only  to  the  umbilicus,  but  in  some  eases  to?  the 
epigastric  region. 

In  males  the  relative  situation  of  the  bladder  and 
rectum  is  such,  that  the  upper  and  middle  part  of 
the  rectum  is  behind  the  bladder ; but  the  lower 
part  of  the  rectum,  following  the  curve  of  the  os 
sacrum  and  coccygis,  is  below  the  posterior  part  of 
the  bladder. 

In  females  the  vagina  and  uterus  are  situated  be- 
tween the  bladder  and  rectum  ; so  that  the  connex- 
ion of  these  last  mentioned  parts  is  very  different  in 
the  two  sexes. 

The  peritoneum  is  reflected  at  the  anterior  part  of 
the  brim  of  the  pelvis  from  the  abdominal  muscles, 
which  it  lines,  to  the  upper  part  of  the  bladder, 
which  is  generally  contiguous  to  the  brim  of  the  pel- 
vis. It  continues  over  to  the  posterior  side  of  the 
bladder,  and  passes  down  upon  it  some  distance  to- 
wards the  lower  part ; but  before  it  has  arrived  at 
the  bottom,  it  is  reflected  towards  the  sacrum. 

In  males  it  extends  from  the  bladder  to  the  rectum, 
and  in  females  to  the  vagina  and  uterus ; so  that  there 
is  a considerable  portion  of  the  lower  part  of  the 
bladder  which  is  not  invested  by  the  peritoneum.  It 
also  follows  that  when  the  bladder  is  extended  into 
the  abdomen,  and  rises  above  the  brim  of  the  pelvis, 
that  part  of  it  which  presents  anteriorly,  and  is  in 
contact  with  the  abdominal  muscles,  is  without  a co- 
vering of  peritoneum,  being  below  it. 

The  bladder  is  composed  of  a coat  consisting  of 
muscular  fibres,  of  a stratum  of  cellular  substance 
immediately  within  this,  and  of  an  internal  lining 


1 64  Muscular  Coal  of  the  Bladder. 

membrane,  which  lias  been  called  villous,  but,  as 
there  are  no  villi  perceptible  on  it,  may  be  more 
properly  denominated  mucous. 

It  should  be  observed,  that,  in  addition  to  these 
coats,  the  bladder  has  a peculiar  investment  of  the 
peritoneum,  as  has  been  already  described;  and 
also  of  the  common  cellular  membrane,  which  is 
placed  between  it  and  every  part  to  which  it  is  con- 
tiguous. 

The  Muscular  Coat  of  the  Bladder  consists  of 
fibres  which  are  not  spread  over  it  of  a uniform  thick- 
ness, but  are  thin  in  some  places,  and  in  others  are 
collected  in  fasciculi.  They  run  in  every  direction: 
some  appear  longitudinal,  others  circular,  and  some 
oblique  ; and  there  are  interstices  between  them 
which  are  occupied  by  cellular  membrane.  The 
longitudinal  fibres  originate  from  the  lower  part  of 
the  bladder ; and  as  this  is  the  fixed  part  of  that 
viscus,  it  is  the  place  from  which  these  fibres  must 
necessarily  act.  These  fibres  are  generally  exterior. 
There  is  no  arrangement  of  muscular  fibres  to  which 
the  term  of  sphincter  can  properly  be  applied  ; but 
many  anatomists  have  thought  that  the  fibres  near 
the  neck  of  the  bladder,  by  their  separate  contrac- 
tion, might  prevent  the  escape  of  urine  ; this  senti- 
ment, however,  is  contrary  to  that  of  several  very 
respectable  writers. 

The  direction  of  the  fibres,  taken  collectively,  is 
such,  that,  when  they  all  contract,  the  cavity  of  the 
bladder  is  completely  obliterated. 

The  cellular  substance  between  the  muscular  and 
internal  coats  is  dense.  It  yields  in  a remarkable 
manner  to  distension,  and  recovers  its  original  dimen- 
sions very  easily.  From  its  analogy  to  a similar 
coat  in  the  intestines,  it  is  called  the  Nervous  Coat. 

The  Internal  Coat  of  the  bladder  is  of  a light  co- 
lour in  the  dead  subject,  when  it  has  been  free  from 


165 


Internal  Coat  of  the  Bladder . 

disease.  It  had  been  called  villous  improperly  ; for 
the  villous  structure  is  not  apparent  upon  its  surface. 
Being  continued  from  the  integuments  of  the  body 
which  are  extended  along  the  urethra,  it  has  been  in- 
ferred, that  the  surface  of  this  coat  was  formed  by  the 
epidermis;  and  some  respectable  authors  have  sup- 
posed that  they  had  seen  cases  in  which  portions  of 
the  epidermis  of  the  bladder  had  separated  and  been 
discharged ; but  these  appearances  are  very  equivo- 
cal, and  it  is  by  no  means  certain  that  an  epidermis 
exists  there.* 

The  fasciculi  of  fibres  of  the  muscular  coat  occasion 
this  coat  to  appear  very  irregular,  but  these  irregula- 
rities correspond  exactly  with  the  arrangement  of  the 
fibres  of  the  muscular  coat. 

When  the  internal  coat  is  separated  by  dissection 
from  the  muscular,  its  surface  is  very  smooth  and 
uniform.  In  the  recent  subject,  when  no  disease 
has  previously  existed,  it  is  always  spread  over  with 
mucous  of  a light  colour,  but  nearly  transparent, 
which  can  be  easily  scraped  off.  This  mucous  is 
spread  upon  the  surface  so  uniformly,  that  it  must 
be  derived  from  sources  which  are  situated  upon 
every  part  of  the  surface  ; but  these  sources  are  not 
very  obvious.  On  the  membrane  of  the  nose  the 
orifices  of  many  mucous  ducts  are  very  visible,  but 
such  orifices  are  not  to  be  seen  on  this  surface. — • 
Haller  mentions  that  he  has  seen  mucous  glands 
near  the  neck  of  the  bladder;  and  it  is  stated  by  the 
pupils  of  Desault,  that,  in  one  of  his  courses,  he 
pointed  out  a number  of  these  glands,  in  a subject 
who  had  been  afflicted  with  a catarrhal  affection  of 
the  bladder. 

* In  the  fauces  and  the  follicles  of  the  tonsils  an  effusion  of  coagulable 
matter,  in  consequence  of  inflammation,  often  forms  crusts,  that  may  be 
mistaken  for  sloughs  of  the  integuments,  although  those  integuments  re- 
main entire. 


166  Mucous  of  the  Bladder. 

Notwithstanding  that  the  sources  of  this  mucous 
are  obscure,  the  quantity  of  it  is  sometimes  immense. 
In  some  cases,  where  the  secretion  is  increased  by 
the  irritation  of  a calculus  in  the  bladder,  the  urine 
is  rendered  somewhat  viscid  and  white  coloured  by 
the  mucous  mixed  with  it ; which,  after  the  urine  has 
been  allowed  to  remain  for  some  time,  subsides  in 
such  quantities  as  demonstrates  that  many  ounces 
must  be  secreted  in  the  course  of  the  twenty-four 
hours.  The  same  circumstances  occur,  without  the 
irritation  of  calculus,  in  the  disease  called  catarrhus 
vesica}.* 

It  is  probable  that,  in  healthy  persons,  a great  deal 
of  it  passes  ofF  unperceived,  being  dissolved  or  dif- 
fused in  the  urine.  From  the  quantity  and  the  regu- 
lar diffusion  of  this  mucous  on  the  surface  of  the 
bladder,  there  is  the  greatest  reason  for  believing 
that  is  is  effused  from  every  part  of  the  surface;  and 
it  is  a question  that  has  not  been  decided  whether  it 
is  discharged  from  glandular  ducts  too  small  to  be 
perceived,  or  from  the  exhalent  extremities  of  the 
blood  vessels.  It  is  probable  that  the  use  of  it  is  to 
defend  the  internal  coat  of  the  bladder  from  the  acri- 
mony of  the  urine. 

The  symptoms  of  a stone  in  the  bladder,  as  well  as 
of  several  other  diseases,  evince  that  this  coat  is  en- 
dued with  a great  degree  of  sensibility. 

It  is  evident  that  the  essential  parts  in  the  general 
structure  of  the  bladder  are  the  muscular  coat  and 
the  internal  coat  last  described : but  in  addition  to 
the  account  of  them,  there  are  some  other  important 
circumstances  to  be  noted  in  the  description  of  this 
organ,  It  has  been  already  stated,  that  the  form  of 
the  bladder  was  an  irregular  oval,  although  it  was 


* In  some  cases  this  mucous  soon  becomes  putrid,  and  during  the  putre- 
factive process  deposits  a substance  which  appears  to  be  calcareous. 


167 


Orifice  of  the  Urethra. 

somewhat  varied  in  different  persons.  The  oval  form 
is  not  much  altered  at  the  part  called  the  neck  of  the 
bladder,  where  the  urethra  passes  off  from  it.  The 
orifice  of  the  urethra  is  situated  anteriority  at  the  low- 
ermost part  of  the  bladder.  On  the  lower  surface  of 
the  urethra,  at  its  commencement,  and  on  the  bottom 
of  the  bladder,  immediately  connected  with  the 
urethra,  is  situated  the  Prostate  Gland,  (to  be  here- 
after described  with  the  organs  of  generation,)  which 
is  a firm  body,  that  adheres  strongly  both  to  the 
bladder  and  urethra.  This  circumstance  gives  par- 
ticular firmness  and  solidity  to  that  part  of  the  blad- 
der. It  has  also  been  observed,  that  the  bladder  is 
attached  firmly  to  the  ossa  pubis,  at  its  neck,  about 
the  origin  of  the  urethra.  Each  of  these  circum- 
stances have  an  effect  upon  the  orifice  of  the  urethra ; 
and  when  the  bladder  is  opened,  and  this  orifice  is 
examined  from  within,  it  appears  to  be  kept  open  by 
the  connexion  of  the  bladder  with  the  prostate,  and 
has  been  very  justly  compared  to  the  opening  of 
the  neck  of  a bottle  into  the  great  cavity  of  that 
vessel.* 

The  orifices  of  the  two  ureters  are  at  equal  dis- 
tances from  the  orifice  of  the  urethra,  and  form  with 
it  the  angles  of  a triangle.  That  part  of  the  internal 
surface  of  the  bladder  which  is  within  this  triangu- 
lar space,  is  more  smooth  than  the  remainder  of  the 
same  surface,  probably  in  consequence  of  the  adhe- 
sion of  the  bladder  to  the  prostate,  and  to  other  parts 
exterior  to  it. 


* The  late  Mr.  Lieutaud,  and  after  him  the  French  anatomists  of  the 
present  day,  have  described  a small  tubercle  at  the  lower  and  posterior 
part  of  the  orifice  of  the  urethra,  which  resembles  the  uvula  in  form.  It 
has  not  been  noticed  here;  and  M.  Boyer  states,  that  it  is  often  scarcely 
perceptible.  He,  however,  makes  a remark  which  is  very  worthy  of  at- 
tention, viz.  that  it  is  very  subject  to  enlargement  in  old  people,  forming  a 
tumour  which  impedes  the  discharge  of  urine.  Sabatier  has  also  made  the 
same  observation. 


168  Ligaments  and  Vessels  of  the  Bladder. 

That  part  of  the  bottom  of  the  bladder  which  is 
immediately  behind  the  triangular  space,  is  rather 
lower  than  this  space;  and  but  a small  portion  of  cel- 
lular membrane  exists  between  it  and  the  rectum  in 
males,  and  the  vagina  in  females. 

The  upper  part  of  the  bladder  is  connected  with 
the  umbilicus  by  means  of  a ligament,  which  passes 
between  the  peritoneum  and  the  abdominal  muscles. 
This  ligament  consists  of  three  cords.  One  of  these, 
which  is  in  the  middle,  arises  from  the  coats  of  the 
bladder,  and  was,  in  the  foetus,  the  duct  called  ura- 
chus; the  other  two,  which  are  connected  to  the 
bladder  principally  by  cellular  membrane,  were  ori- 
ginally the  umbilical  arteries.*  The  middle  cord  is 
of  a light  colour  and  fibrous  structure ; it  is  thickest 
at  the  bladder,  and  gradually  diminishes  as  it  ap- 
proaches the  umbilicus.  In  a few  instances  it  has 
been  found  to  be  hollow.  In  its  progress  to  the  umbi- 
licus it  becomes  more  or  less  blended  with  the  linea 
alba  or  the  tendons  of  the  abdominal  muscles.  The 
other  cords  are  generally  solid.  After  passing  from 
the  umbilicus  to  the  bladder,  they  continue  on  the 
sides  of  that  viscus,  and  finally  terminate  at  the  hy- 
pogastric or  internal  iliac  artery. 

In  the  very  young  subject  these  cords  are  invested 
by  distinct  processes  of  the  peritoneum,  but  their 
position  is  exterior  to  the  peritoneum. 

As  the  bladder  is  situated  very  near  most  of  the 
large  ramifications  of  the  hypogastric  artery  in  the 
pelvis,  it  receives  branches  from  several  of  them; 
viz.  from  the  umbilical  arteries  before  they  termi- 
nate ; from  the  pubic ; from  the  obturators,  &c.  These 
branches  ramify  in  the  cellular  membrane  exterior 
to  the  muscular  coat,  and  also  in  the  cellular  sub- 
stance between  the  muscular  and  internal  coats.  It 

* See  the  accounts  of  these  parts  in  the  description  of  the  Abdomen  of 

the  Foetus. 


General  Obsei'vations. 


169 


has  been  conjectured,  that  their  terminations  in  ex- 
halents  on  the  surface  of  the  bladder  are  remarkably 
numerous. 

The  veins  correspond  with  the  arteries,  but  they 
are  very  numerous  on  the  lower  and  lateral  parts  of 
the  bladder,  and  by  uniting  with  the  veins  of  the 
rectum  form  a remarkable  plexus. 

The  Lymphatic  Vessels  of  this  organ  do  not  appear 
more  numerous  than  those  of  other  parts.  They  pass 
on  each  side  the  bladder  in  the  course  of  its  blood 
vessels,  and  unite  with  the  larger  lymphatics,  and 
the  glands  which  lie  upon  the  great  blood  vessels  on 
the  sides  of  the  pelvis. 

The  JYerves  of  the  bladder  are  derived  both  from 
the  intercostal  nerve  and  from  the  nerves  of  the  me- 
dulla spinalis,  which  pass  off  through  the  sacrum  ; 
and  therefore  the  bladder  is  more  affected  than  the 
viscera  of  the  abdomen,  by  injuries  of  the  medulla 
spinalis. 

The  action  of  the  muscular  fibres  of  the  bladder  in  ex- 
pelling urine,  and  the  effect  of  those  fibres  which  are 
situated  near  the  orifice  of  the  urethra  in  retaining  it, 
can  be  considered  with  more  advantage  after  the  struc- 
ture of  the  urethra  and  the  muscles  connected  with 
that  canal  have  been  described. 

It  has  been  stated,  that  the  internal  coat  of  the  blad- 
der is  very  sensible ; but  it  may  be  added,  that  in 
consequence  of  disease  about  the  neck  of  the  bladder, 
the  natural  sensibility  appears  most  inordinately  in- 
creased. When  the  intensity  of  pain  which  accom- 
panies these  complaints,  the  frequent  recurrence  of 
paroxysms,  and  their  duration,  are  taken  into  view, 
there  seems  reason  to  believe  that  none  of  the  painful 
affections  of  the  human  race  exceed  those  which  arise 
from  certain  diseases  of  the  bladder  Happily  these 
diseases  are  not  very  common. 

The  functions  of  the  kidneys  is  to  secret  urine,  :nd 
that  of  the  bladder  to  retain  it,  until  the  proper  time 
for  evacuation. 

Voi..  xr,  22 


170 


General  Observations. 


The  urine  may  be  regarded  as  an  excrementitious 
fluid,  which  contains  many  substances  in  solution  that 
are  constantly  found  in  it,  and  many  others  that  are 
occasionally  in  it,  which  are  taken  as  aliment  or  me- 
dicine, and  pass  to  the  bladder  with  little,  if  any, 
change.  The  odour  of  the  rose  leaf,  the  colour  of 
rhubarb,  &c.  are  occasionally  perceived  in  urine. 

The  substances  constantly  found  in  urine  are  nume- 
rous. THe  chemical  account  of  the  subject  is  so  long, 
that  it  cannot  be  detailed  here ; but  the  student  ought 
to  make  himself  acquainted  with  it,  and  he  will  read 
with  great  advantage  Johnson’s  History  of  Animal 
Chemistry,  vol.  2d,  page  363  ; and  also  Thompson’s 
Elements  of  Chemistry,  page  333. 


CHAPTER  V. 


OF  THE  MALE  ORGANS  OF  GENERATION. 

These  organs  consist,  1st,  of  the  Testicles,  and 
their  appendages. 

2d.  Of  certain  parts  denominated  the  Vesiculse 
Seminales  and  the  Prostate  Gland , which  are  situ- 
ated near  the  commencement  of  the  urethra,  and  are 
subservient  to  the  purposes  of  generation. 

3d.  Of  the  Penis. 

SECTION  I. 

Of  the  Testicles  and  their  Appendages „ 

The  Testicles  are  two  bodies  of  a flattened  oval 
form.  Each  of  them  has  a protuberance  on  its  upper 
and  posterior  part  called  Epididymis , and  is  connect- 
ed to  parts  within  the  cavity  of  the  abdomen  by  a 
thick  cord,  which  proceeds  to  it  through  the  abdo- 
minal ring.  Each  testicle  also  appears  to  be  contain- 
ed in  a sac,  which  is  suspended  by  this  cord  and  co- 
vered by  the  common  integuments. 

That  portion  of  the  common  integuments  which 
forms  the  external  covering  of  the  testicles,  is  deno- 
minated 

The  Scrotum . 

The  skin  of  the  scrotum,  although  it  is  very  often 
in  a state  of  corrugation,  has  the  same  structure  with 
that  on  other  parts  of  the  body,  except  that  it  is 


3 *2  Structure  of  the  Scrotum . 

lather  thiner  and  more  delieate.  The  superior  deli- 
cacy of  this  portion  of  the  skin  is  evinced  by  the  great 
irritation  produced  by  the  application  of  stimulating 
substances,  and  the  desquamation  of  the  cuticle,  which 
seems  to  be  the  effect  of  irritation.  There  are  many 
sebaceous  follicles  in  this  portion  of  skin  ; and  after 
puberty  there  are  often  a few  long  hairs  growing  out 
of  it,  the  bulbs  of  which  are  often  very  conspicuous. 
There  is  a small  raised  line  in  the  middle  of  this 
skin,  which  commences  at  the  root  of  the  penis,  and 
proceeds  backwards,  dividing  it  into  two  equal  parts: 
this  line  is  denominated  Raphe. 

The  corrugation  which  so-  often  takes  place  in  the 
skin  of  the  scrotum,  appears  to  be  occasioned  by  the 
contraction  of  certain  fibres,  which  are  in  the  cellu- 
lar substance  immediately  within  it.  This  cellular 
substance  appears  to  be  attached  in  a particular  way 
to  the  skin  ; and  it  also  invests  each  testicle  in  such 
a manner,  that  when  they  are  withdrawn  a cavity  is 
left  in  it.  It  has  long  been  observed,  that  no  adipose 
matter  is  found  in  this  cellular  substance  ; but  it  is 
often  distended  with  water  in  hydropic  diseases. 
As  the  contraction  and  corrugation  of  the  scrotum 
has  been  imputed  to  this  substance,  it  has  been  ex- 
amined with  particular  attention  by  anatomists,  and 
very  different  sentiments  have  been  entertained  re- 
specting it.  While  some  dissectors  have  asserted 
that  muscular  fibres  could  be  seen  in  it,  which  they 
have  denominated  the  Dartos  Muscle ,*  others  have 
said  that  this  substance  was  simply  cellular,  and 
without  any  muscular  fibres.  This  difference  of  sen- 
timent may  possibly  have  arisen  from  the  different 
conditions  of  this  part  in  different  subjects  ; for  in 
some  cases  there  are  appearances  which  seem  to  jus- 
tify the  assertion  that  muscular  fibres  exist  in  this 
structure. 

After  the  testicles  are  removed,  so  as  to  leave  the 


173 


Action  of  the  Dartos  Muscle . 

cellular  substance  connected  with  the  skin,  if  the  scro- 
tum be  inverted,  and  this  substance  examined  in  a 
strong  light,  many  fibres  will  appear  superadded  to 
the  common  cellular  structure  ; and  sometimes  their 
colour  can  be  distinguished  to  be  red.  It  is  not  as- 
serted that  this  will  be  uniformly  the  case ; but  cer- 
tainly it  has  often  been  observed  in  this  way. 

The  existence  of  an  organ  which  possesses  the 
power  of  contraction,  within  the  skin  of  the  scrotum 
and  connected  to  it,  is  evinced  by  the  corrugation 
which  takes  place  when  the  scrotum  is  suddenly  ex- 
posed to  cold,  after  having  been  very  warm.  This 
corrugation  occurs  in  a very  sudden  and  rapid  man- 
ner, in  some  cases,  in  which  the  wounded  scrotum 
is  thus  exposed  for  the  purpose  of  dressing  : for  ex- 
ample, upon  removing  an  emollient  poultice  from 
this  part  some  days  after  the  operation  for  the  cure 
of  hydrops  testis,  by  incision,  if  the  air  of  the  cham- 
ber be  cool,  a motion  of  the  scrotum  will  take  place, 
almost  equal  to  the  peristaltic  movements  of  the  in- 
testines. 

The  Arteries  of  the  scrotum  are  derived  from  two 
sources.  One  or  two  small  arteries,  which  arise  from 
the  femoral  artery,  between  Poupart’s  ligament  and 
the  origin  of  the  profunda,  are  spent  upon  it.  These 
are  called  the  external  pudic  arteries.  It  also  re- 
ceives some  small  branches  from  the  internal  pudic 
artery. 

The  Nerves  of  the  scrotum  are  principally  derived 
from  the  lumbar  nerves. 

The  Spermatic  Cord. 

The  cord  which  proceeds  to  the  testicle  through 
the  abdominal  ring,  appears  at  first  view  like  a bun- 
dle of  muscular  fibres ; but  it  consists  of  an  artery 
and  veins,  with  many  lymphatic  vessels  and  nerves, 
and  also  the  excretory  duct  of  the  testicle,  connected 


174  Cremaster  Muscle. —Blood  vessels  of  the  Testicle . 

to  each  other  by  cellular  substance,  and  covered  by 
an  expansion  of  muscular  fibres  which  are  derived 
from  the  lower  edge  of  the  internal  oblique  muscle  of 
the  abdomen,  and  continue  from  it  to  the  upper  part 
of  the  testicle.  These  fibres  constitute  the  Cremas- 
ter Muscle. 

The  artery  above  mentioned  is  called  the  Sperma- 
tic. It  commonly  arises  from  the  front  of  the  aorta, 
very  near  its  fellow,  at  a small  distance  below  the 
emulgents : and  is  not  much  larger  than  a crow’s 
quill.  It  proceeds  downwards  behind  the  perito- 
neum and  before  the  psoas  muscle  and  ureter. — 
While  it  is  in  contact  with  the  psoas  muscle,  it  joins 
the  ramifications  of  the  vein.  It  afterwards  meets 
the  vas  deferens,  and  proceeds  through  the  abdomi- 
nal ring  to  the  back  part  of  the  testis.  Before  it  ar- 
rives at  the  testis  it  divides  into  several  branches, 
two  of  which  generally  go  to  the  epididymis,  and  the 
others  penetrate  the  tunica  albuginea  on  the  upper 
and  back  of  the  testicle,  and  ramify  very  minutely 
on  the  fine  membranous  partitions  which  exist  in  that 
body. 

In  addition  to  the  spermatic  artery,  there  is  a small 
twig  from  the  umbilical  branch  of  the  hypogastric* 
which  passes  to  the  spermatic  cord  along  the  vas  de- 
ferens. 

The  branches  of  the  spermatic  vein  are  much  larg- 
er than  those  of  the  artery:  several  of  them  proceed 
from  the  testicle  so  as  to  correspond  with  the  arterial 
branches ; and  in  addition  to  these  there  are  many 
smaller,  which  also  arise  from  the  testicle  and  epidi- 
dymis. In  their  course  up  the  cord  they  ramify, 
and  again  unite,  so  as  to  form  a considerable  plexus, 
which  is  called  the  Corpus  Pampiniforme , and  con- 
stitutes a considerable  part  of  the  volume  of  the  sper- 
matic cord. 

As  they  proceed  upwards  they  unite  into  a few 


Lymphatics  and  Nerves  of  the  Spermatic  Cord.  175 

larger  veins  ; and  finally,  on  the  psoas  muscle,  they 
generally  form  one  trunk,  which  continues  upwards 
so  as  to  unite  with  the  vena  cava  on  the  right  side, 
and  the  emulgent  vein  on  the  left. 

Sometimes,  but  not  often,  there  are  several  sper- 
matic veins  on  each  side. 

The  Lymphatic  Vessels  of  the  testicle  are  very  nu- 
merous, considering  the  size  of  the  organ.  Six  or 
eight,  and  sometimes  more,  large  trunks  have  been 
injected,  running  upon  the  cord,  and  continuing  to 
the  glands  on  the  back  part  of  the  abdomen. 

The  JYerves  of  the  testicle  are  derived  from  those 
which  supply  the  viscera  of  the  abdomen,  and  are  to 
be  found  in  the  cord  although  they  can  scarcely  be 
traced  to  the  testicle.  A small  plexus,  called  the 
spermatic,  is  formed  by  fibres  from  the  renal  plexus 
and  from  the  sympathetic  nerve.  These  fibres  ac- 
company the  spermatic  vessels,  and  in  all  probability 
enter  the  body  of  the  testis  and  the  epididymis.  The 
spermatic  cord  and  cremaster  muscle  receive  filaments 
from  the  second  lumbar  nerve. 

In  addition  to  these  vessels,  the  Vas  Deferens, 
which  is  much  firmer  than  either  of  them,  is  always 
to  be  distinguished  in  the  back  part  of  the  cord. 

They  are  all  covered  in  front  and  on  the  sides  by 
the  cremaster  muscle,  which  passes  with  them  from 
the  lower  margin  of  the  internal  oblique,  through  the 
abdominal  ring,  and  continues  to  the  upper  part  of 
the  external  coat  of  the  testicle,  which  is  a sac  appa- 
rently containing  that  organ,  and  upon  this  sac  it  is 
spread  out  and  terminates. 

The  Tunica  Vaginalis . 

The  External  Coat  of  the  testicle,  which  is  com- 
monly called  the  Tunica  Vaginalis , is  a complete 
sac  which  encloses  the  testicle  as  the  pericaridum 
encloses  the  heart.  It  covers  the  body  of  the  testicle 


176 


Coals  of  the  Testicle . 

and  epididymis,  and  adheres  closely  to  them.  It  is 
then  reflected  from  them  so  as  to  form  a loose  sac, 
which  appears  to  contain  them.  The  cavity  of  the 
tunica  vaginalis  commonly  extends  above  the  body  of 
the  testis  up  the  cord,  and  is  oval  or  pyriform. — This 
sac  is  so  reflected  from  the  body  of  the  testicle  that 
there  is  a place  on  the  upper  and  back  part  of  that 
body,  at  which  the  blood  vessels  enter  it,  without 
penetrating  the  sac. 

It  resembles  the  peritoneum  and  other  serous  mem- 
branes in  texture,  and  is  therefore  thin  and  delicate. 
It  always  contains  a quantity  of  moisture,  sufficient  to 
lubricate  the  surface  which  it  forms. 

When  the  tunica  vaginalis  is  lain  open,  the  testicle 
appears  as  if  it  were  contained  in  the  posterior  part 
of  its  cavity. 

The  testicles,  as  has  been  already  stated,  are  of  a 
flattened  oval  form.  Their  position  is  somewhat 
oblique,  so  that  their  upper  extremities  look  upwards 
and  forwards,  their  lower  extremities  downwards 
and  backwards,  and  their  edges  present  forwards  and 
backwards. 

The  body  of  the  testicle  is  very  firm,  in  conse-  J 
quence  of  its  enclosure  in  a very  firm  coat  called  Tu- 
nica Albuginea.  Upon  the  upper  and  posterior  part 
of  it  is  the  protuberant  substance,  called  Epididymis , 
which  is  less  firm,  being  exterior  to  the  tunica  albu- 
ginea. The  blood  vessels  of  the  testicle  pass  into  it 
on  the  posterior  edge,  at  some  distance  below  the 
upper  end. 

The  Tunica  Albuginea , 

In  which  the  body  of  the  testicle  is  completely 
enclosed,  is  firm  and  dense ; and  upon  this  coat  its 
particular  form  depends.  It  is  of  a whitish  colour, 
and  has  a smooth  external  surface.  It  is  thick  as 
well  as  strong.  The  epididymis  is  exterior  to  it. 


Form  and  Connexions  of  the  Epididymis . 177 

It  is  only  perforated  by  the  blood  vessels,  lympha- 
tics and  nerves,  and  by  the  vasa  efferentia,  which 
carry  out  the  secretion  of  the  testis.  One  portion  of 
the  tunica  vaginalis  adheres  very  closely  to  it,  and 
the  other  appears  to  contain  it.  The  portion  which 
adheres  to  it  is  with  difficulty  separated,  but  it  is  a 
distinct  membrane. 

The  Epididymis. 

Differs  in  colour  from  the  testicle,  being  more  or 
less  reddish.  It  commences  at  the  upper  and  ante- 
rior extremity  of  the  testicle,  and  passes  down  the 
posterior  edge  to  the  lower  end. 

At  the  commencement  the  epididymis  is  somewhat 
rounded  in  form,  and  its  upper  part,  or  head,  has 
been  called  the  globus  major : as  it  descends  it 
lessens,  and  about  the  middle  of  the  testicle  it  is 
flatfish. 

It  is  firmly  attached  to  the  body  of  the  testicle,  at 
the  upper  end,  where  the  vasa  efferentia  pass  to  it ; 
and  it  is  also  attached  to  it  below  ; but  at  the  middle 
it  appears  nearly  detached  from  it.  It  has  therefore 
been  compared  to  an  arch  resting  with  its  two  extre- 
mities on  the  back  of  the  testis  ; it  is,  however,  in 
contact  with  it  at  its  middle  ; but  about  the  middle 
it  only  adheres  by  one  of  its  edges  to  the  body  of 
the  testis,  and  generally  by  its  internal  edge.  It  has 
a coat  which  is  less  firm  than  the  tunica  albuginea  of 
the  testicle,  described  on  the  last  page.  The  tunica 
vaginalis  of  the  testicle  is  so  reflected  as  to  cover  a 
great  part  of  the  epididymis  which  is  not  in  contact 
with  the  testicle,  and  also  those  surfaces  of  the  epi- 
didymis and  testis  which  are  in  contact  with  each 
other  and  do  not  adhere. 

The  Body  of  the  Testicle. 

When  the  tunica  albuginea  is  cut  through,  and 
the  substance  of  the  testicle  examined,  it  appears 

Vol,  iio  23 


178  Tubuli,  Septa  and  Bloodvessels  of  the  Testicle » 

to  consist  of  a soft  pulpy  substance  of  convoluted 
threads,  of  a yellowish  brown  colour,  which  is  divi- 
ded into  separate  portions  by  very  delicate  septa,  at- 
tached to  the  internal  surface  of  the  tunica  albuginea 
at  the  posterior  part  of  the  testicle.  After  macera- 
tion, by  using  a fine  needle  to  detach  them  from  the 
cellular  substance,  these  threads  may  be  drawn  out  to 
a great  length.  In  some  animals  they  are  larger  than 
in  the  human  species  ; in  them,  it  is  said,  they  are 
evidently  hollow,  and  that  very  small  blood  vessels 
appear  in  their  Goats.  When  mercury  is  injected 
into  the  vas  deferens,  or  excretory  duct  of  the  testis, 
in  a retrograde  course,  it  can  be  perceived  in  these 
ducts  in  the  human  subject. 

These  delicate  septa,  or  partitions,  are  united  to 
the  internal  surface  of  the  tunica  albuginea  at  the 
posterior  part  of  the  testicle,  at  which  place  there  is 
a body  called  Corpus  Highmorianum,  which  has 
been  regarded  very  differently  by  different  anato- 
mists. It  is  a long  whitish  substance*  which  extends 
lengthwise  on  the  posterior  part  of  the  testis ; and 
was  supposed  by  Haller  to  resemble  one  of  the  sali- 
vary ducts.  It  is  now,  however,  generally  agreed  to 
be  of  a cellular  structure,  and  to  contain  and  support 
the  ducts  which  pass  from  the  substance  of  the  testi- 
cle to  the  epididymis. 

The  blood  vessels  pass  into  the  body  of  the  testi- 
cle upon  these  septa,  and  are  continued  from  them  to 
the  filaments  or  tubes  of  which  the  body  of  the  testi- 
cle consists.  As  in  some  animals  blood  vessels  are 
distinguished  on  these  tubes,  there  is  the  greatest 
reason  to  believe  that  a direct  communication  sub- 
sists between  them,  without  the  intervention  of  any 
other  structure,  no  other  structure  having  been  dis- 
covered : but  at  the  same  time  it  ought  to  be  obser- 
ved, that  these  tubes  have  not  yet  been  injected  from 
the  blood  vessels.  Some  ingenious  anatomists  have 


Blood  vessels  and  Structure  of  the  Testicle,  fyc.  179 

injected  the  artery  going  to  the  testicle  so  success- 
fully, that  the  injection  has  passed  from  it  into  the 
veins  coming  out  of  the  testicle ; but  it  is  not  now 
said  by  any  of  them,  that  they  have  filled  the  tubes 
in  this  manner. 

Mercury  will  pass  into  these  vessels  from  the  ex- 
cretory duct  of  the  testicle  ; and  by  means  of  an  in- 
jection in  that  way,  the  structure  of  the  testiele  can 

be  unravelled. 

'this  structure  is  as  follows : The  cavity  formed 
by  the  tunica  albuginea  is  divided  into  a number  of 
apartments  by  the  very  thin  septa,  or  partitions, 
above  mentioned.  From  the  filamentary  or  tubular 
matter  which  fills  each  of  these  chambers,  proceeds 
a number  of  small  tubes  or  vessels,  which  observe  a 
straight  course  ; they  are  therefore  called  Vasa  Recta . 
These  vasa  recta  unite  with  each  other  and  form  a 
net-work  on  the  back  of  the  testis,  within  the  tunica 
albuginea,  which  is  called  Rete  Testis.  From  this 
net-work  other  vessels,  from  twelve  to  eighteen  in 
number,  denominated  Vasa  Ejferentia , proceed 
through  the  albuginea  to  the  epididymis.  These 
vessels  are  convoluted  in  such  a manner  as  to  form 
bundles  of  a conical  form,  which  are  called  Coni 
Vasculosi.  The  number  of  these  corresponds  with 
the  number  of  the  vasa  efferentia,  and  they  com- 
pose about  one  third  of  the  epididymis,  viz.  all  the 
upper  part  of  it.  The  single  tubes  which  form  each 
of  these  cones,  successively  unite  into  one  duct,  which 
is  convoluted  so  as  to  form  all  the  remainder  of  the 
epididymis.  The  lower  part  of  the  epididymis  is 
turned  upwards  on  the  back  of  the  testicle,  the  tube 
gradually  enlarges  and  is  less  convoluted,  and  finally 
becomes  straight : it  then  takes  the  name  of  Vas  De- 
ferens, and  continues  on  the  back  of  the  testicle  and 


ISO  Course  of  the  Vas  Deferens. 

at  the  inner  side  of  the  epididymis  to  the  spermatic 
cord.*f 

A small  solitary  vessel  or  duct,  has  been  observed 
by  Haller,  Monro,  and  several  other  anatomists,  to 
proceed  from  the  upper  part  of  the  epididymis  : 
sometimes  it  Unites  to  the  epididymis  below,  and 
sometimes  it  proceeds  upwards.  The  nature  of- this 
vessel  has  not  been  ascertained  with  certainty. 

The  Vas  Deferens 

Is  a very  firm  tube  about  one  line  in  diameter, 
which  is  not  perfectly  cylindrical  exteriorly,  although 
the  cavity  formed  by  it  is  so.  This  cavity  is  so  small 
in  diameter,  that  it  will  only  admit  a fine  bristle. 
The  coats  of  the  duct  have,  of  course,  a considera- 
ble thickness.  The  internal  coat  forms  a soft  sur- 
face, analogous  to  that  of  the  mucous  membranes  : 
the  external  is  firm,  and  its  texture  resembles  that 
of  cartilage.  Owing  to  the  small  size  of  the  cavity, 
the  internal  coat  has  not  been  separated  from  the  ex- 
ternal. 

* De  Graff  appears  to  have  been  the  first  anatomist  who  made  much 
progress  in  the  successful  investigation  of  the  structure  of  the  testicle  ; 
and  Haller  ought  to  be  mentioned  next  to  him,  on  account  of  the  plate  ex- 
hibiting this  structure,  and  the  explanation  of  it,  which  he  published  in  the 
Philosophical  transactions  of  London,  for  1749.  This  plate  has  been  re- 
published by  the  second  Monro,  in  the  Literary  and  Physical  Essays  of 
Edinburgh,  and  also  in  his  Inaugural  Thesis.  Haller  has  likewise  repub- 
lished it  in  his  Opera  Minora.  It  represents  not  only  the  vasa  efferentia 
and  the  cones  formed  by  their  convolutions,  but  also  the  rete  testis  and  the 
vasa  recta.  Haller  could  inject  no  further  than  this ; but  Monro  and 
Hunter  soon  after  succeeded  so  as  to  fill  a considerable  portion  of  the  body 
of  the  testicle  with  mercury,  injected  by  the  vas  deferens. 

f In  Mr.  Charles  Bell’s  Anatomical  collection  in  London,  there  is  a pre- 
paration by  his  assistant,  Mr.  Shaw,  in  which  the  tubuli  testis  are  com- 
pletely injected  with  quicksilver  and  unravelled.  I saw  also  in  Leyden, 
one  nearly  as  successfully  executed  by  Professor  Sandifort.' — Ed. 


181 


Course  of  the  Vas  Deferens. 

It  passes  upwards  in  the  posterior  part  of  the 
spermatic  cord,  and  continues  with  it  through  the 
abdominal  ring,  under  and  exterior  to  the  perito- 
neum ; soon  after  this  it  leaves  the  cord  and  dips 
down  into  the  cavity  of  the  pelvis,  forming  a curve 
on  the  side  of  the  bladder,  and  proceeding  back- 
wards, downwards  and  inwards.  In  this  course  it 
crosses  the  ureter,  and  passes  between  it  and  the 
bladder.  On  the  lower  part  of  the  bladder  the  two 
vasa  deferentia  approach  each  other  so  gradually, 
that  they  appear  to  be  nearly  parallel.  They  pro- 
ceed forward  between  the  vesiculse  seminales,  which 
are  two  bodies  irregularly  convoluted,  that  are  placed 
in  a converging  position  with  respect  to  each  other, 
and  communicate  with  the  vasa  deferentia.  The 
vasa  deferentia  finally  terminate  almost  in  contact 
with  each  other  in  the  posterior  part  of  the  prostate 
gland,  where  they  perforate  the  urethra.  At  the 
distance  of  about  two  inches  and  a half  from  their 
termination  they  enlarge  in  diameter,  and  become 
somewhat  convoluted.  At  the  posterior  margin  of 
the  prostate  they,  come  in  contact  with  the  anterior 
extremities  of  the  vesiculse  seminales,  and  unite  with 
them.  After  this  union  they  diminish  in  size,  and 
become  conical ; and  passing  a short  distance  through 
the  substance  of  the  prostate,  during  which  they  ap- 
proach each  other  more  rapidly,  they  penetrate  the 
urethra,  so  as.  to  open  in  it  on  each  side  of  a small 
tubercle,  called  the  Caput  Gallinaginis}  seon  to  be 
described. 

SECTION  II, 

. Of  the  Vesiculse  Seminales  and  the  Prostate  Glands 

The  Vesiculse  Seminales  are  two  bodies  of  a 
whitish  colour,  and  irregular  form,  being  broad  and 
flat  at  their  posterior  extremities,  and  terminating  in 


182  Structure  of  the  Vesiculse  Siminaies , 

a point  at  the  other.  Their  surfaces  are  so  convo- 
luted, that  they  have  been  compared  to  those  of  the 
brain.  They  are  situated  between  the  rectum  and 
bladder,  and  are  connected  to  each  by  cellular  mem- 
brane. 

When  the  vesiculse  seminales  are  laid  open  by  an 
incision,  they  appear  to  consist  of  cells  of  a consider- 
able size,  irregularly  arranged ; but  when  they  are 
carefully  examined  exteriorly,  and  the  cellular  mem- 
brane about  them  is  detached  and  divided,  they  ap- 
pear to  be  formed  by  a tube  of  rather  more  than  two 
lines  diameter,  and  several  inches  in  length,  which 
terminates,  like  the  caecum,  in  a closed  extremity.? — * 
From  this  tube  proceed  from  ten  to  fifteen  short 
branches,  which  are  closed  in  the  same  manner.-— 
All  these  tubes  are  convoluted  so  as  to  assume  the 
form  of  the  visiculm  seminales  above  described ; and 
they  are  fixed  in  this  convoluted  state  by  cellular 
membrane,  which  firmly  connects  their  different  parts 
to  each  other.  It  is  obvious,  that  tubes  thus  convo- 
luted, when  cut  into,  will  exhibit  the  appearance  of 
cells,  as  in  the  present  instance. 

This  convoluted  tube  composing  the  vesiculse  se-  3 
minales,  terminates  in  a very  short  duct,  which  is 
nearly  of  the  same  diameter  with  the  vas  deferens, 
and  this  duct  joins  the  vas  deferens  so  as  to  form  an' 
acute  angle. 

From  the  union  of  the  vesicylss  seminales  with  the 
vas  deferens  on  each  side,  a canal,  which  seems  to 
be  the  continuation  of  the  vas  deferens,  proceeds  i 
through  part  of  the  prostate  to  the  urethra,  which  it 
perforates.  These  canals  are  from  eight  to  twelve 
lines  in  length  ; they  are  conical  in  form,  their  3 
largest  extremity  being  equal  to  the  vas  deferens  at  ' 1 
that  part. 

If  air  or  any  other  fluid  be  injected  through  the 
vas  deferens  into  the  urethra,  it  will  pass  at  the  same 


Function  of  the  Vesieulse  Seminales . 183 

time  into  the  vesieulse  seminales,  and  distend  them. 
It  has  been  observed,  that  a fluid  passes  in  this  man- 
ner much  more  readily  from  the  vasa  deferentia  into 
the  vesieulae  seminales,  than  it  does  from  these  last 
mentioned  organs  into  the  duct. 

These  organs  were  generally  regarded  as  reservoirs 
of  semen,  and  analogous  to  the  gall  bladder  in  their 
functions,  until  the  late  Mr.  J.  Hunter  published  his 
opinion  that  they  were  not  intended  to  contain  semen, 
but  to  secrete  a peculiar  mucous  subservient  to  the 
purposes  of  generation. 

He  states  the  following  facts  in  support  of  his  opin- 
ion. 

A fluid,  very  different  from  semen,  is  found  after 
death  in  the  vesieulse  seminales. 

In  persons  who  have  lost  one  testicle,  a consider- 
able time  before  death,  the  vesieulse  seminales  on 
each  side  are  equally  distended  with  this  peculiar 
fluid.  In  the  case  of  a person  who  had  a deficiency 
of  the  epididymis  on  one  side  and  of  the  vas  deferens 
on  the  other,  the  vesieulse  were  filled  with  their  pe- 
culiar fluid  S 

The  sensation  arising  from  redundance  of  the  se- 
cretion of  the  testes,  is  referred  to  the  testes,  and 
not  to  the  vesieulse  seminales. 

In  some  animals  there  is  no  connexion  between 
the  vasa  deferentia  and  the  vesieulae  seminales. 

See  Observations  on  certain  parts  of  the  Animal 
Economy,  by  John  Hunter*. 

The  Prostate  Gland. 

Is  situated  on  the  under  and  posterior  part  of  the 
neck  of  the  bladder,  so  as  to  surround  the  urethra. 
Its  form  has  some  resemblance  to  that  of  the  ches- 
nut,  but  it  has  a notch  on  the  basis  like  that  of  the 
figure  of  the  heart  on  playing  cards,  and  it  is  much 
larger  than  the  chesnufc  of  this  part  of  America,, 


184  Prostate  Gland.* — The  Penis. 

The  basis  of  this  body  is  posterior,  and  its  apex  an- 
terior; its  position  is  oblique,  between  the  rectum  and 
the  symphisis  pubis.  Below  there  is  in  some  cases  a 
small  furrow,  which,  in  addition  to  the  notch  above, 
gives  to  the  gland  an  appearance  of  being  divided  into 
two  lobes.  By  turning  away  the  vesicul®  seminales 
and  vasa  deferentia  from  the  under  surface  of  the 
bladder  we  bring  into  view  a small  tubercle  at  the 
upper  part  of  the  base  of  the  prostate,  called  by  Sir 
Everard  Home  the  third  lobe.  When  diseased  it 
projects  into  the  cavity  of  the  bladder. 

It  adheres  to  the  urethra  and  neck  of  the  bladder. 
Its  consistence  is  very  firm  and  dense,  resembling  the 
induration  of  scirrhus  rather  more  than  the  ordinary, 
texture  of  glands. 

This  gland  receives  small  branches  from  the  neigh- 
bouring blood  vessels,  and  has  no  artery  of  consider- 
able size  exclusively  appropriated  to  it. 

As  it  lies  in  close  contact  with  the  urethra,  the 
ducts  which  pass  between  it  and  the  urethra  are  not 
to  be  seen  separate  from  these  bodies ; but  ducts  can 
be  seen  in  the  substance  of  the  gland,  which  perfo- 
rate the  urethra,  and  open  on  the  sides  of  the  caput 
gallinaginis  to  the  number  of  five  or  six  on  each  side. 
By  pressure  a small  quantity  of  a whitish  fluid  can 
be  forced  from  these  orifices,  which  is  rather  viscid, 
and  coagulable  in  alcohol. 

The  particular  use  of  this  fluid  is  not  known. 

SECTION  III. 

Of  the  Penis . 

The  penis,  when  detached  from  the  bladder,  and 
the  bones,  to  which  it  is  connected,  and  divested  of 
the  skin  which  covers  it,  is  an  oblong  body,  which 
is  rounded  at  one  extremity  and  bifurcated  at  the 

other. 


Perns.  1&5 

It  is  composed  of  three  parts,  viz  two  oblong  bo- 
dies, called  Corpora  Cavernosa , which,  at  their  com- 
mencement, form  the  bifurcated  portions,  and  then 
unite  to  compose  the  body  of  the  organ ; and  a third 
part,  of  a spongy  texture,  which  is  connected  to  these 
bodies  where  they  unite  to  each  other,  on  the  under 
side,  and  continues  attached  to  them  during  the  whole 
extent  of  their  union,  terminating  in  an  expanded 
head  which  covers  the  anterior  extremities  of  the 
corpora  cavernosa.  The  urethra  passes  from  the 
neck  of  the  bladder,  on  the  under  side  of  the  penis, 
to  its  anterior  extremity,  invested  by  this  third  body, 
which  is  therefore  called  Corpus  Spongiosum  Ure- 
thrae. 

The  two  bifurcated  extremities  are  attached  each 
of  them  to  one  of  the  crura  of  the  pubis  and  ischium ; 
and  they  unite  to  form  the  body  of  the  penis  imme- 
diately anterior  to  the  symphisis  pubis,  to  which  the 
lower  part  of  it  is  also  attached ; so  that  the  penis  is 
firmly  connected  to  the  middle  of  the  anterior  part  of 
the  pelvis.  The  urethra  proceeds  from  the  neck  of 
the  bladder,  between  the  crura  of  the  ischium  and 
pubis  and  the  crura  of  the  penis,  to  join  the  body  of 
the  penis  at  its  commencement,  and  near  this  place 
its  connexion  with  the  corpus  spongiosum  begins;  so 
that  there  is  a small  portion  of  the  urethra  between 
the  neck  of  the  bladder  and  the  commencement  of  the 
corpus  spongiosum,  which  is  not  covered  by  the  cor- 
pus spongiosum.  This  is  called  the  membranous  part 
of  the  urethra. 

The  penis,  therefore,  consists  of  two  oblong  bo- 
dies of  a cellular  structure,  which  originate  separate- 
ly, but  unite  together  to  form  it ; and  of  the  urethra, 
which  joins  these  bodies  immediately  after  their 
union,  an$  is  invested  by  a spongy  covering,  which 
by  its  expansion  forms  the  anterior  extremity  not 
. only  of  the  urethra  but  of  the  whole  penis.  These 

Vol,  ii.  24 


186  Corpora , Cavernosa  Penis . 

three  bodies,  thus  arranged  and  connected,  are  cover* 
ed  by  cellular  membrane  and  skin  in  a manner  to  be 
hereafter  described. 

The  Corpora  Cavernosa , 

Which  compose  the  body  of  the  penis,  are  two  ir- 
regular cylinders,  that  are  formed  by  a thick  dense 
elastic  membrane,  of  a whitish  ligamentous  appear- 
ance and  great  firmness.  They  are  filled  with  a sub- 
stance of  a cellular  structure,  which  is  occasionally 
distended  with  blood.  The  crura  of  these  cylindri- 
cal bodies,  which  are  attached  to  the  crura  of  the 
ischium  and  pubis,  are  small  and  pointed  at  the  com- 
mencement, and  are  united  to  the  periosteum  of  the 
bones.  In  their  progress  upwards  they  enlarge,  and 
at  the  symphisis  of  the  pubis  they  unite  so  as  to  form 
an  oblong  body,  which  retains  the  appearance  of  a 
union  of  two  cylinders  applied  to  each  other  length- 
ways ; for  above  there  is  a superficial  groove  passing" 
in  that  direction,  which  is  occupied  by  a large  vein : 
and  below  there  is  a much  deeper  groove,  in  which 
the  urethra  is  placed.  Between  these  grooves  is  a 
septum  which  divides  one  side  of  the  penis  from  the 
other.  It  appears  to  proceed  from  the  strong  mem- 
brane which  forms  the  penis,  and  is  composed  of 
bundles  of  fibres,  which  pass  from  one  groove  of  the 
penis  to  the  other,  with  many  intervals  between  them, 
through  which  blood  or  injection  passes  very  freely. 
Sometimes  these  bundles  of  fibres,  with  their  inter- 
vals,  are  so  regularly  arranged,  that  they  have  been 
compared  to  the  teeth  of  a comb.  This  septum  ex- 
tends from  the  union  of  the  two  crura  to  their  termi-  ;i 
nation. 

Each  of  these  cylinders  is  penetrated  by  the  main 
branch  of  the  pudic  artery,  which  is  about  equal  in 
size  to  a crow’s  quill.  These  arteries  enter  the  cor- 
pora cavernosa  near  their  union,  and  continue 


181 


Cells  of  the  Corpora  Cavernosa „ 

through  their  whole  extent,  sending  off  branches  in 
their  course ; the  turgeseence  and  erection  of  the  penis 
is  unquestionably  produced  by  the  blood  which  flows 
through  these  vessels  into  the  penis. 

The  interior  structure  of  the  penis,  when  examined 
in  the  recent  subject,  is  of  a soft  spongy  nature,  and 
seems  stained  with  blood.  If  any  fluid  be  injected 
through  the  arteries  this  substance  appears  cellular, 
and  may  be  completely  distended  by  it.  When  air 
is  injected,  and  the  structure  becomes  dry,  the  penis 
may  be  laid  open ; the  cellular  structure  then  appears 
as  if  formed  by  a number  of  lamina  and  of  filaments, 
which  proceed  from  one  part  of  the  internal  surface 
of  the  penis  to  another,  and  form  irregular  cells.  It 
has  been  compared  to  thq  lattice-work  in  the  interior 
of  bones  j "and  it  is  suggested  by  M.  Roux,  that  the 
fibres  of  which  the  structure  consists  resemble  those 
of  the  strong  elastic  coat  of  the  penis.*  If  these  cells 
are  filled  with  coloured  wax,  injected  by  the  artery, 
and  the  animal  substance  is  then  destroyed  by  placing 
the  preparation  in  a corroding  liquor,  the  wax  which 
remains  shows  that  the  membranes  forming  the  cells 
are  very  thin. 

These  cells  communicate  freely  with  tfeaeh  other  ; 
and  therefore,  if  a pipe  be  passed  through  the  strong 
coat  of  the  penis,  the  whole  of  them  can  be  filled  from 
it  by  the  ordinary  process  of  injection. 

* Mr.  John  Hunter  says  on  this  subject,  “ That  the  cells  of  the  corpora 
cavernosa  are  muscular,  although  no  such  appearance  is  to  be  observed  in 
men  ; for  the  penis  in  erection  is  not  at  all  times  equally  distended.  Tke 
penis,  in  a cold  day,  is  not  so  large  in  erection  as  in  a warm  one  : which 
probably  arises  from  a kind  of  spasm,  that  could  not  act  if  it  were  not  mus= 
eular. 

In  the  horse,  the  parts  composing  the  cells  of  the  penis  appear  evident- 
ly muscular  to  the  eye,  and  in  a horse  just  killed,  they  contract  upon  being 
stimulated.”— Ed. 


188 


Corpus  Spongiosum.— Bulb, 

The  Urethra. 

Is  a membranous  canal,  which  extends  from  the 
neck  of  the  bladder  to  the  orifice  at  the  extremity  of 
the  penis ; and  for  a very  great  part  of  its  length  is 
invested  by  a spongy  structure,  called  the  corpus 
spongiosum  urethrae.  It  proceeds  from  the  neck  of 
the  bladder  along  the  upper  part  of  the  prostate; 
from  the  prostate  it  continues  between  the  crura  of 
the  penis  until  their  junction:  it  then  occupies  the 
great  groove  formed  by  the  corpora  cavernosa  on  the 
lower  side  of  the  penis,  and  continues  to  the  orifice 
above  mentioned.  At  a small  distance  from  the  pros- 
tate gland  the  spongy  substance  which  invests  it  com- 
mences, and  continues  to  its  termination.  After  this 
spongy  substance  has  arrived  at  the  termination  of 
the  corpora  cavernosa,  it  expands  and  forms  a body 
of  a particular  figure  which  covers  the  extremities 
of  the  corpora  cavernosa,  and  is  denominated  the 
Gians  Penis. 

The  Corpus  Spongiosum  begins  at  the  distance  of 
eight  or  ten  lines  from  the  anterior  part  of  the  pros- 
tate.* It  is  much  larger  at  its  commencement  than  at 
any  other  part  except  the  glans,  and  this  enlarged 
part  is  called  the  Bulb.  It  surrounds  the  whole  of 
the  urethra,  and  with  the  exception  Of  the  bulb  and 
the  glans  penis,  is  of  a cylindrical  figure.  It  is  form- 
ed by  a membrane  which  has  some  resemblance  to  the 
coat  of  the  penis,  but  is  much  thinner,  and  by  a pe- 
culiar spongy  substance,  which  occupies  the  space  be- 
tween the  internal  surface  of  this  membrane  and  the 
external  surface  of  the  canal  of  the  urethra.  The 
membrane  and  the  spongy  substance,  form  a coat  to 
the  urethra,  which,  with  the  exception  of  the  enlarge- 
ment before  mentioned,  is  about  one  line  thick.  After 
this  spongy  substance  has  arrived  at  the  termination,, 
its  coat  adheres  firmiy  to  the  coat  of  the  penis. 


Structure  of  the  Corpus  Spongiosum.  189 

The  Bulb,  or  first  enlargement  of  the  corpus  spon- 
giosum, is  oblong,  and  rather  oval  in  form  ; it  is  mark- 
ed by  a longitudinal  depression  in  the  middle,  which 
is  very  superficial.  It  consists  entirely  of  the  spongy 
substance  above  mentioned. 

The  Gians  Penis  is  also  composed  of  the  same 
spongy  substance,  but  the  coat  which  covers  it  is 
more  thin  and  delicate  than  that  of  the  other  parts  of 
the  urethra.  The  lower  surface  of  the  glans  is  fitted 
to'  the  extremities  of  the  corpora  cavernosa,  but  it  is 
broader  than  the  corpora  cavernosa,  and  therefore 
projects  over  them  on  the  upper  and  lateral  parts  of 
the  surface  of  the  penis.  The  edge  of  the  promi- 
nent part  is  regularly  rounded,  and  is  denominated 
the  Corona  Glandis. 

Several  small  arteries  pass  to  this  spongy  structure. 
The  pudic  artery,  as  it  passes  on  each  side  to  the  cor- 
pora cavernosa,  sends  a branch  to  the  bulb  of  the 
urethra.  The  same  vessel  in  the  substance  of  the 
penis,  also  sends  branches  to  the  urethra  : and  the 
artery  on  the  back  of  the  penis  terminates  in  small 
branches,  which  penetrate  the  substance  of  the  glans. 

By  these  vessels  blood  is  carried  to  the  spongy 
substance  of  the  urethra,  which  is  occasionally  dis- 
tended in  the  same  manner  that  the  cavernous  bodies 
of  the  penis  are  distended  during  the  erection  of  that 
organ.  But  the  cellular  structure,  of  this  organ  is 
not  so  unequivocal  as  that  of  the  corpora  cavernosa ; 
for  if  it  be  injected  with  coloured  wax,  and  corroded 
in  the  usual  manner,  the  injected  matter  will  exhibit 
an  appearance  which  has  the  strongest  resemblance 
to  a convoluted  vessel,  like  the  vas  deferens  in  the 
epididymis.* 

* Mr.  Hunter  says,  “ that  the  corpus  spongiosum  urethrse  and  glans 
penis  are  not  spongy  or  cellular,  but  made  up  of  a plexus  of  veins.  This 
structure  is  discernible  in  the  human  subject ; but  is  much  more  distinctly 
sees,  in  many  animals,  as  the  horse,”  &e  — - Ep. 


190 


Internal  Surface  of  the  Urethra . 

The  Canal  of  the  Urethra , 

Which  conveys  the  urine  from  the  bladder,  is  a very 
important  part  of  the  urinary  organs.  It  consists  of 
a vascular  membrane  with  a smooth  surface,  which  is 
perforated  by  the  qrifices  of  many  mucous  follicles, 
some  of  which  are  of  considerable  size.  It  is  ex- 
tremely sensible,  and  has  so  much  power  of  contrac- 
tion, that  some  persons  have  supposed  muscular 
fibres  to  exist  in  its  structure. 

It  is  dilferently  circumstanced  in  different  parts  of 
its  course.  While  surrounded  with  the  prostate  it  ad- 
heres firmly  to  that  body,  seeming  to  be  supported  by 
it ; and  here  its  diameter  is  larger  than  it  is  farther 
forward.  On  the  lower  or  posterior  side  of  this  por- 
tion of  the  urethra,  is  an  oblong  eminence,  called 
Verumontanum,  or  Caput  Cfallinaginis , which  com- 
mences at  the  orifice  of  the  urethra,  and  continues 
throughout  the  whole  portion  that  is  surrounded  by 
the  prostate  gland,  terminating  at  the  point  of  that 
body.  The  posterior  extremity  of  this  tubercle  begins 
abrupt^,  and  soon  becomes  thick  and  large  ; ante- 
riorly it  gradually  diminishes  to  a line,  which  is  some- 
times perceptible  for  a considerable  distance  in  the 
urethra,  in  a straight  forward  direction.  In  the  upper 
edge  or  top  of  this  body  is  a groove,  which ‘is  produced 
by  a mucous  follicle  ; on  the  lateral  surfaces,  anterior 
to  the  middle,  are  the  orifices  of  the  common  ducts  of 
the  vesiculse  seminales  and  vasa  deferentia,  (see  page 
182,)  which  are  sufficiently  large  to  receive  a thick 
bristle.  N ear  these,  on  each  side,  are  five  or  six  smaller 
orifices  of  the  excretory  ducts  of  the  prostate  gland. 
At  the  distance  of  an  inch  before  the  extremity  of  the 
bulb  of  the  urethra,  in  the  lining  membrane,  are  the 
openings  of  two  ducts,  one  on  each  side,  that  lead  to 
small  glandular  bodies  called  Cowper’s  glands,  which 
are  situated  on  each  side  of  the  urethra  below  the  bulb, 
but  are  covered  bv  the  accelerator es  urinse  muscles. 

v <• 


191 


Mucous  Ducts  of  the  Urethra. 

The  diameter  of  the  urethra  lessens  after  it  leaves 
the  prostate.  That  portion  of  the  canal  which  is  be- 
tween  this  gland  and  the  bulb,  without  investment, 
and  therefore  called  the  membranous  part,  is  the 
smallest  in  diameter. 

After  it  is  invested  with  the  spongy  substance,  it 
has  a small  enlargement,  and  then  continues  nearly 
of  one  size,  until  it  arrives  near  the  glans  penis,  when 
it  again  enlarges  and  alters  its  form,  being  no  longer 
cylindrical  but  flattened.  Its  broad  surfaces  have 
now  a lateral  aspect. 

From  the  bulb  of  the  corpus  spongiosum  to  this 
last  enlargement,  the  appearance  of  the  inner  surface 
of  the  urethra  is  uniform.  The  membrane  is  thin 
and  delicate,  and  in  a healthy  subject,  who  has  been 
free  from  disease  of  these  parts,  is  of  a whitish  co- 
lour ; but  blood  vessels  are  very  perceptible  in  it. 
When  it  is  relaxed,  it  appears  to  be  thrown  into 
longitudinal  wrinkles;  but  it  admits  of  considerable 
extension,  being  somewhat  elastic : when  extended, 
its  surface,  appears  smooth,  as  if  it  were  covered 
with  an  .epithelium.  Mr.  Shaw,  of  London,  has 
described  a set  of  vessels  immediately  below  the  in- 
ternal membrane  of  the  urethra,  which,  when  empty, 
are  very  similar  in  appearance  to  muscular  fibres.— 
He  says  he  has  discovered  that  these  vessels  form 
an  internal  spongy  body,  which  passes  down  to  the 
membranous  .part  of  the  urethra,  and  forms  even  a 
small  bulb  there.  His  preparation  with  a quicksilver 
injection  of  the  part  is  certainly  a very  satisfactory 
proof  of  its  existence.*  Throughout  the  whole  ex- 
tent of  this  part  of  the' urethra,  are  the  orifices  of  a 
great  many  mucous  ducts  or  sinuses,  which  pass 
obliquely  backwards.  Many  of  these  are  so  small 
that  they  cannot  be  penetrated  by  a bristle,  or  probe 

* Sea  Sled,  Clururg—Tfansactions  of  Londca— vol  10th. 


192  Mucous  Dads  of  the  Urethra a 

of  that  size;  but  some  are  larger.  It  has  not  been 
observed  that  any  glandular  body  immediately  sur- 
rounds them,  although  they  secrete  the  mucous  with 
which  the  urethra  is  lubricated. — On  the  lower  side 
of  the  urethra,  near  the  commencement  of  the  glans 
penis,  there  is  one  or  more  of  them,  so  large  that 
their  orifices  sometimes  admit  the  point  of  a small 
bougie.* 

These  organs,  when  inflamed,  secrete  the  puriform 
discharge  which  takes  place  in  gonorrhoea. — In  a na- 
tural state  they  produce 'the  mucous  which  is  con* 
stantly  spread  over  the  surface  of  the  urethra,  to  de- 
fend it  from  the  acrimony  of  the  urine,  and  which 
passes  away  with  that  fluid  unperceived. 

The  surface  of  the  urethra  is  endued  with  great 
sensibility,  and  is  therefore  liable  to  great  irritation 
from  contact  with  any  rough  body  or  any  acrid  sub- 
stance. Irritation,  thus  excited,  induces  a state  of 
contraction,  which  is  particularly  remarkable,  as  no 
muscular  fibres  are  to  be  seen  in  its  structure. — When 
a bougie  has  been  passed  into  the  urethra  for  a consi- 
derable distance,  if  it  cannot  proceed  the  whole  way, 
it  sometimes  happens  that  the  instrument  will  be  dis- 
charged by  a steady  uniform  motion,  which  seems  to 
proceed  from  a progressive  contraction  of  the  urethra, 
beginning  very  low  down.  At  particular  times,  after 
the  urethra  has  been  much  irritated,  it  will  not  receive 
a bougie,  although  at  other  times  a bougie  of  equal 
size  may  be  passed  to  the  bladder  without  opposition. 
This  cannot  depend  upon  that  elasticity  which  was 
noticed  before. f 

* They  were  discovered  by  Plazzoni,  of  Padua,  in  1621.  Their  number, 
according  to  Loder,  amounts  to  about  65 — See  his  plates.  Ed. 

f Sir  Everard  Home,  whose  professional  opinions  are  of'  great  weight, 
has  lately  described  in  the  Transactions  of  the  Royal  Society,  the  appear- 
ance of  the  lining  membrane  of  the  Urethra,  when  viewed  through  a 


Contractile  Power  of  the  Vrethra . 19J 

Upon  the  two  crura  of  the  penis,  or  the  beginning 
of  the  corpora  cavernosa,  are  fixed  the  muscles  call- 
ed Ereetores  Penis,  which  are  described  in  the  first 
volume.*  These  muscles  cover  the  crura  of  the 
penis  from  their  origin  to  their  junction,  and  not 
only  compress  them,  but  also  influence  the  motion  oi 
the  penis  when  it  is  distended. 

The  bulb  of  the  urethra  is  covered  by  a muscular 
coat,  called  the  Accelerator  Urinse  * which  has  the 
effect  of  driving  forwards  any  fluid  contained  in  the 
cavity  of  the  urethra,  and  also  of  giving  the  same 
direction  to  the  blood  in  that  part  of  the  corpus 
spongiosum.  There  is  also  the  Transversus  Perinei 
on  each  side,  that  passes  transversely  from  the  tube- 
rosity of  the  ischium  to  the  bulb  of  the  urethra.— 
Finally  the  lower  part  of  the  sphincter  ani  muscle, 
which  is  nearly  elliptical  in  form  is  inserted  by  its 
anterior  point  into  the  muscular  covering  of  the  bulb 
of  the  urethra.  Upon  removing  the  integuments, 
these  muscles  are  in  view ; and  the  course  of  the 
urethra  from  the  bladder  is  concealed,  particularly 
by  the  anterior  point  of  the  sphincter  ani.  When 
the  sphincter  ani  is  dissected  away  from  its  anterior 
connexions,  and  the  cellular  and  adipose  substance, 
which  is  sometimes  very  abundant,  is  also  removed, 
the  lower  surface  of  the  membranous  part  of  the 
urethra  may  be  brought  into  view,  as  it  proceeds 
from  the  prostate  gland  to  the  balb  of  the  corpus 
spongiosum.f 


microscope  of  great  powers.  From  this  paper  it  seems  that  he  is  full/ 
convinced  of  its  muscular  structure. — Ed. 

* See  description  of  “ Muscles  about  the  Male  Organs  of  Generation,' 
Vol.  I.  Part  II.  Chap.  II. 

t The  natural  situation  of  the  membranous  part  of  the  urethra,  and  of 
the  prostate  gland,  as  well  as  their  relative  position  with  respect  to  the 
sphincter  ani,  rectum,  &c.  can  be  best  stadied  by  a lateral  view  of  the 

Tol,  ii,  25 


194  Contractile  Power  of  the  Urethra . 

When  the  accelerator  u rinse  is  removed  from  the 
bulb  of  the  urethra,  there  will  appear  two  bodies, 
which  have  some  resemblance  to  flattened  peas. 
They  lie  one  on  each  side  of  the  urethra,  in  contact 
or  nearly  so  with  its  bulb,  and  from  each  gland  pro- 
ceeds an  excretory  duct  of  an  inch  and  a quarter  in 
length,  between  the  corpus  spongiosum  and  the  lining 
membrane  of  the  canal  of  the  urethra,  and  opens  into 
the  latter.  Its  orifice  is  found  with  some  difficulty, 
but  is  large  enough  to  admit  a bristle.  These  are 
Cowper’s  glands.^ 

The  penis  is  connected  to  the  symphisis  pubis  by 
a ligamentous  substance,  which  proceeds  from  the 
back  or  upper  surface  of  the  organ  to  the  anterior 
part  of  the  symphisis,  and  connects  these  parts  firm- 
ly to  each  other. 

Thus  constructed,  of  the  corpora  cavernosa  and 
the  urethra  with  its  corpus  spongiosum,  and  attach- 
ed to  the  pelvis  as  above  mentioned,  the  penis  is  in- 
vested with  its  integuments  in  the  following  man- 
ner, f 

contents  of  the  pelvis ; which  is  to  be  obtained  by  removing  carefully 
one  of  the  ossa  innominata,  and  dissecting  the  parts  which  were  enclosed 
by  it. 

* These  glands  were  discovered  by  Mery,  in  1684,  and  described  by 
Cowper,  in  1699.  A third  gland,  smaller  than  the  preceding,  connected 
with  the  curve  of  the  urethra  under  the  symphisis  pubis,  was  discovered  by 
Cowper,  and  Morgagni  speaks  of  having  observed  a fourth. — Ed. 

t There  are  several  fasciae  and  ligaments  about  the  perineum  which 
should  be  connected  with  the  account  of  its  viscera.  Immediately  beneath 
the  skin  of  the  perineum  is  the  Perineal  Fascia,  a thin  but  strong  mem- 
brane, which  extends  from  bone  to  bone,  occupying  the  space  between 
the  anus  and  the  posterior  part  of  the  scrotum.  It  is  rather  better  seen  in 
lean  subjects  than  in  fat  ones,  for  in  the  latter  it  is  converted  in  part  into 
adipose  membrane.  When  a rupture  occurs  in  the  posterior  part  of 
the  urethra,  this  fascia  prevents  the  urine  from  showing  itself  immedi- 
ately in  the  perineum,  and  drives  it  into  the  cellular  structure  of  the 
scrotum. 

Immediately  beneath  the  perineal  faseia  are  placed  the  muscles ; when 
they  are  removed  the  bulb  of  the  urethra  may  be  seen  very  advantage- 
ously; extending  in  the  middle  of  the  perineum  almost  to  the  anus.  It  is 


Integuments  of  the  Penis . 


195 


Integuments  of  the  Penis . 

The  glans  penis,  the  structure  of  which  has  been 
already  described,  is  covered  by  a continuation  of 
the  skin,  which  appears  altered  in  its  texture  so  as 
to  resemble  in  some  respects  the  skin  of  the  lips,  and 
in  like  manner  is  covered  by  a delicate  production 
of  cuticle. 

Around  the  corona  of  the  glans,  especially  on  its 
upper  part,  there  are  whitish  tubercles,  which  are  of 
different  sizes  in  different  persons,  but  always  very 
small.  The  skin  adheres  firmly  to  the  whole  extent 
of  the  corona  of  the  glans,  and  is  very  delicate  in  its 
structure  as  it  continues  from  the  glans  upon  the 
body  of  the  penis ; but  it  gradually  changes  so  as  to 
assume  the  appearance  and  structure  of  a common 
skin,  and  continues  in  this  state  over  the  penis.  The 
adhesion  of  the  skin  to  the  ligamentous  coat  of  the 
corpora  cavernosa  also  becomes  more  loose,  owing 
to  the  quantity  and  texture  of  the  cellular  substance 
which  connects  them.  The  skin  thus  connected  to 
the  penis,  has  commonly  more  length  than  that  or- 
gan, even  in  its  extended  state.  In  consequence  of 
this  greater  length,  and  of  its  adhering  firmly  around 
the  corona  glandis,  it  necessarily  forms  a circular 

not  loose  and  pendulous,  but  is  attached  by  its  pelvic  surface  to  the  trian- 
gular ligament  of  the  urethra.  This  ligament  is  a septum  between  the 
perineum  and  the  pelvis,  and  connects  itself  to  the  pelvic  or  internal 
edges  of  the  rami  of  the  pubis  and  ischii  as  far  down  as  the  organs  of  the 
crura  penis.  It  extends  from  the  arch  of  the  pubis  to  the  line  mentioned, 
and  fills  up  all  the  space  between  the  bones  of  the  opposite  sides.  It 
consists  of  two  lamina,  and  Cowper’s  glands  are  placed  between  them. 
About  an  inch  below  the  symphisis  pubis  a perforation  is  made  in  this  lig- 
ament for  the  passage  of  the  membranous  part  of  the  urethra. 

Just  below  the  symphisis  pubis,  between  the  two  lamina  of  the  triangu- 
lar ligament,  is  placed  a much  stronger  ligament  called  the  pubic,  which  is 
about  half  an  inch  broad,  its  lower  edge  is  thick  and  rounded.  For  further 
detail  on  the  subject  of  the:fasciae  of  the  pelvis  see  Lessons  in  Practical 
Anatomy  by  the  present  editor.— Ep. 


A 96  Integuments  of  the  Penis, 

fold  or  plait,  which  varies  in  size  according  to  the 
length  of  the  skin.  This  fold  is  generally  situated  at 
the  commencement  of  the  firm  attachment  of  the  skin 
to  the  body  of  the  penis,  or  around  the  glans;  but  it 
may  be  formed  any  where  upon  the  body  of  the  penis 
by  artificial  management. 

This  duplicature,  or  fold  of  the  skin,  when  it  takes 
place  so  as  to  cover  the  glans,  is  called  the  Prepuce ; 
and  the  skin  which  is  very  tender  and  delicate  for 
some  distance  from  the  glans,  form  that  surface  of  the 
prepuce  which  is  in  contact  with  the  glans  when  it 
covers  that  body. 

There  is  also  a small  fold  of  the  skin,  which  is 
longitudinal  in  its  direction,  that  commences  at  the 
orifice  of  the  urethra,  and  extends  backwards,  on  the 
lower  surface  of  the  penis.  It  is  unvarying  in  its 
position,  and  is  called  the  Frenum. 

It  is  a general  observation,  that  adeps  is  not  found 
in  the  cellular  substance  which  connects  the  skin  to 
the  body  of  the  penis ; but  this  cellular  substance  is 
distended  with  water  in  some  hydropic  cases. 

From  the  skin  immediately  below  the  glans,  and 
from  small  follicles  on  each  side  of  the  frenum,  is 
secreted  an  unctuous  fluid,  which,  when  allowed  to 
continue,  becomes  inspissated,  and  acquires  a caseous 
consistence  and  colour,  as  well  as  a peculiar  odour. 
It  sometimes  also  acquires  an  acrimony  which  produ- 
ces inflammation  on  the  surface  with  which  it  is  in 
contact,  as  well  as  the  copious  seeretion  of  puriform 
fluid. 

The  distribution  of  the  pudic  artery  in  the  penis, 
has  already  been  mentioned;  and  a further  account 
of  its  origin  and  progress  to  its  destination,  will  be 
found  in  the  general  account  of  the  arteries.  Some- 
times small  branches  of  the  external  pudic  arteries, 
which  originate  from  the  femoral,  are  extended  to 
the  penis;  and  it  has  been  asserted,  that  branches  of 


Blood  Vessels  and  Absorbents  of  the  Penis . 19/ 

the  middle  hsemorrhoidal  artery  have  also  been  found 
there,  but  this  does  not  often  occur. 

The  Veins  of  the  penis  are  of  two  kinds : those 
which  originate  in  the  corpora  cavernosa,  accompany 
the  corresponding  branches  of  the  pudic  artery,  but 
communicate  more  or  less  with  the  plexus  of  veins 
on  the  lower  and  lateral  part  of  the  bladder.  There 
is  also  a great  vein,  which  occupies  the  groove  on 
the  back  of  the  penis,  between  the  corpora  caver- 
nosa, that  appears  particularly  appropriated  to  the 
corpus  spongiosum  urethrae ; for  it  originates  in  the 
glans  penis,  and  receives  branches  from  the  urethra 
as  it  proceeds  backwards.  There  are  often  two  of 
these  veins,  one  in  the  groove,  and  the  other  more 
superficial : they  generally  unite  near  the  root  of  the 
penis.  The  common  trunk  then  passes  between  the 
body  of  the  penis  and  the  symphisis  pubis,  and  ter- 
minates in  a plexus  of  veins  at  the  neck  of  the  blad- 
der, which  is  connected  to  the  plexus  above  men- 
tioned on  the  lower  and  lateral  parts  of  the  same 
viscus. 

The  Absorbent  Vessels  of  the  penis  take  two  differ- 
ent directions  on  each  side.  Those  which  arise  from 
the  integuments  generally,  unite  so  as  to  form  a few 
trunks  on  the  back  of  the  penis,  which  divide  near 
the  root  of  the  organ,  and  proceed  to  the  glands  of 
the  groin.  Those  which  originate  from  the  interior 
parts  of  the  penis,  accompany  the  blood  vessels,  and 
terminate  in  the  plexus  of  lymphatics  in  the  pelvis. 

It  ought  to  be  noted,  that  the  superficial  lympha- 
tics generally  enter  the  upper  inguinal  glands. 

The  JYerves  of  the  penis  are  principally  derived 
from  the  lower  secral  nerves,  which  unite  in  the 
plexus  that  forms  the  great  ischiatic.  From  these 
nerves  a branch  on  each  side  originates,  which  passes 
like  the  pudic  artery,  between  the  sacro-sciatic  liga- 
ments. In  this  course  it  divides  into  two  branches,  one 


198 


JVerves. -^General  Observations. 


of  which  passes  below  to  the  museles  of  the  penis  and 
urethra,  and  to  the  contiguous  parts ; and  some  of 
its  branches  seem  finally  to  terminate  in  the  dartos : 
the  other  branch  proceeds  along  the  crura  of  the  pu- 
bis and  ischium,  and  passing  between  the  symphisis 
pubis  and  the  body  of  the  penis,  arrives  at  the  upper 
surface  or  dorsum  of  the  penis,  along  which  it  conti- 
nues on  the  outside  of  the  veins  to  the  glans,  in  which 
it  terminates.  In  this  course  it  sends  off  several 
branches,  some  of  which  terminate  in  the  integuments 
of  the  penis. 

After  an  examination  of  the  relative  situation  of  the  mus- 
cles and  blood  vessels  of  the  male  organs  of  genaration, 
there  appears  reason  to  doubt,  whether  the  erection  of 
the  penis  can  be  referred  to  pressure  upon  the  veins 
which  return  from  that  organ.  Albinus  has  written  on 
this  subject.  See  Academicarum  Annotationum,  lib. 
ii.  caput  xviii.  Haller  has  also  considered  it,  and 
stated  the  opinions  of  several  anatomists,  in  bis  Ele- 
menta  Physiologiae,  tom.  vii.  page  555. 

The  manner  in  which  the  urine  is  confined  in  the  blad- 
der does  not  appear  to  be  clearly  understood.  The 
connexion  of  the  neck  of  the  bladder  with  the  prostate, 
and  the  appearance  of  the  contiguous  parts  of  the  blad- 
der, do  not  render  it  probable  that  these  parts  act  like 
a sphincter.  The  late  J.  Hunter,  who  paid  great  at- 
tention to  the  functions  of  these  organs,  was  very  de- 
cided in  his  opinion  that  the  contraction  of  the  urethra 

Iiroduced  the  effect  of  a sphincter  of  the  bladder.  He 
las  published  some  very  ingenious  observations  respect- 
ing the  manner  in  which  urine  is  discharged  from  the 
bladder,  in  his  Treatise  on  the  Venereal  Disease,  part 
III.  chapter  IX. 

Mr.  Hunter  also  long  since  asserted,  that  the  vascular 
convoluted  appearance  of  the  corpus  spongiosum  ure- 
thrae was  more  distinct  in  the  horse  than  the  man.  In 
the  fifth  volume  of  the  Lemons  d’Anatomie  Comparee 
of  Cuvier,  the  very  learned  and  ingenious  author  con- 
firms the  declaration  of  Hunter,  respecting  the  vascu- 
lar convolutions  of  the  corpus  spongiosum  of  the  horse. 
He  states,  that  the  corpora  cavernosa  of  the  penis  of 
the  elephant  appear  to  be  filled  in  a great  degree  with 


General  Observations . 


199 


the  ramifications  of  veins,  which  communicate  with  each 
other  by  such  large  and  frequent  anastomoses,  that  they 
have  a cellular  appearance.  A similar  structure  exists 
in  the  horse,  camel,  bullock,  deer,  &c.  and  in  them  all 
these  communicating  branches  can  be  distinguished 
from  those  which  extend  the  whole  length  of  the  penis. 

The  corpus  spongiosum  urethrae,  according  to  M.  Cu- 
vier, is  constructed  in  a similar  manner.  From  these 
facts  he  is  induced  to  believe  that  this  structure  per- 
vades the  whole  class  of  mammalia. 


CHAPTER  VL 


OF  THE  FEMALE  ORGANS  OF  GENERATION, 

The  female  organs  of  generation  consist  of  the 
Uterus  and  Ovaries , with  their  appendages ; and  of 
the  Vagina , with  the  structure  which  surrounds  its 
external  orifice.  The  uterus  is  situated  in  the  pelvis, 
between  the  bladder  and  rectum ; and  the  ovaries 
are  on  each  side  of  it.  The  vagina  is  a very  large 
membranous  canal,  which  passes  from  the  uterus 
downwards  and  forwards,  also  between  the  bladder 
and  rectum,  and  opens  externally. 

Connected  with  the  orifice  of  the  vagina  are  seve- 
ral bodies,  which  are  called  the  external  parts  of 
generation , in  order  to  distinguish  them  from  the 
uterus  and  ovaries,  and  their  appendages,  and  also 
from  the  canal  of  the  vagina ; which  are  called  the 
internal  parts. 

The  bladder  of  urine  lies  above  and  in  contact  with 
the  vagina  : the  urethra  is  also  intimately  connected 
with  it.  The  description  of  the  bladder  and  urethra 
is  therefore  placed  at  the  end  of  this  chapter. 

SECTION  I. 

Of  the  External  Parts  of  Generation. 

The  adipose  membrane,  immediately  anterior  to 
the  symphisis  pubis,  and  on  each  side  of  it,  forms  a 
considerable  prominence  in  females,  which,  at  the  age 
of  puberty,  is  covered  with  hair,  as  in  males.  This 
prominence  is  denominated  the  Mons  Veneris. 

The  exterior  orifice  commences  immediately  be- 
low this.  On.  each  side  of  this  orifice  is  a nronfib 


Labia  Externa. — Clitoris.  2gi 

uence  continued  from  the  mons  veneris,  which  is 
largest  above,  and  gradually  diminishes  as  it  descends. 
These  prominences  have  some  hair  upon  them.  They 
are  called  the  Labia  Externa.  Their  junction  be 
low  is  denominated  the  Fourchette.  The  space  be- 
tween the  place  of  their  junction  and  the  anus  is  ra- 
ther more  than  an  inch  in  extent,  and  is  denominated 
the  Perineum. 

As  the  skin  which  forms  the  labia  is  continued  in- 
ternally, it  becomes  more  thin  and  soft,  and  is  cover 
ed  by  a more  delicate  cuticle.  It  is  also  more  or  less 
florid,  and  secretes  a peculiar  mucous. 

In  the  upper  angle,  formed  by  the  labia  externa, 
is  the  upper  extremity  and  glans  of  the  clitoris. 

The  Clitoris  is  a body  which  has  a very  strong 
resemblance  to  the  penis,  but  there  is  no  urethra  at 
taehed  to  it.  It  has  two  crura  of  considerable  length, 
which  originate,  like  those  of  the  penis,  from  the 
crura  of  the  pubis  and  ischium,  and  unite  at  the 
symphisis  of  the  pubis  so  as  to  form  a body,  which 
is  not  much  more  than  an  inch  in  length,  and  is 
broad  in  proportion.  The  extremity  of  this  organ, 
called  the  Gians  of  the  Clitoris , forms  a small  tu- 
bercle, which  is  covered  above  and  on  the  sides  by  a 
small  plait  or  fold  of  the  skin,  denominated  the  Pre- 
puce. These  parts  are  lubricated  by  a secretion 
similar  to  that  which  is  observed  round  the  glans 
penis. 

The  crura  of  the  clitoris  have  muscles  similar  to 
the  erectores  penis.  The  interior  structure  of  the 
Clitoris  is  very  similar  to  that  of  the  corpora  caver- 
nosa of  the  penis,  or  the  corpus  spongiosum  of  the 
urethra.  It  appears  constructed  for  a similar  disten- 
tion, and  is  endued  with  the  same  sensibility  as  the 
penis.  The  two  lateral  parts  are  also  separated  from 
each  other  by  a septum,  resembling  that  of  the  penis. 
It  is  united  to  the  symphisis  pubis  by  a ligament 
Vol.'h,  " 26 


^02  JVyniphse .* — Hymen , 

The  Prepuce  of  the  clitoris  lias  a semicircular 
form  : below  its  extremities  two  folds  or  plaits  com 
mence,  one  on  each  side,  which  are  situated  obliquely 
with  respect  to  each  other,  so  as  to  form  an  angle. 
These  folds  are  denominated  the  Nymphsc. 

The  Nymphse  extend  from  the  clitoris  downwards 
nearly  as  far  as  the  middle  of  the  orifice  of  the  vagina. 
They  are  situated  within  the  external  labia,  and  are 
formed  by  the  skin  after  it  has  become  more  delicate 
in  its  texture.  Their  surface  however.is  often  some- 
what corrugated.  There  are  many  blood  vessels  in 
their  internal  structure,  and  it  is  supposed  they  are 
occasionally  somewhat  tumid.  They  are  flat,  and 
their  exterior  edge  is  convex;  so  that  they  are  nar- 
row at  their  extremities,  and  broad  in  the  middle. 
Their  breadth  is  very  variable,  and  in  some  instances 
is  great.  In  a majority  of  cases,  it  is  equal  to  one- 
fourth  of  their  length.  Their  colour  in  young  sub- 
jects is  of  a bright  red;  in  women  advanced  in  years 
and  who  have  had  many  children,  they  are  of  a brown 
red,  and  sometimes  of  a dark  colour. 

The  use  of  these  parts  is  not  very  evident.  They 
have  been  supposed  to  regulate  the  course  of  the 
urine  as  it  flows  from  the  urethra,  but  their  effect  in 
tliis  respect  is  not  great.  They  have  also  been  sup- 
posed to  favour  the  necessary  enlargement  of  the 
parts  in  parturition. 

The  orifice  of  the  urethra  is  situated  about  an  inch 
and  one  quarter  further  inward  than  the  clitoris.  It  A 
is  often  rathe®  less  than  the  diameter  of  the  urethra, 
and  is  somewhat  protuberant.  The  orifices  of  mu- 
cous ducts  arq  to  be  perceived  around  it. 

The  orifice  of  the  urethra  is  at  the  commencement 
of  the  Canal  of  the  vagina.  Immediately  within 
this  orifice  is  situated  the  membrane  denominated  f 
Hymen . 

The  Hymen  is  an  incomplete  septum,  made  by  a * 


203 


The  Vagina. 

fold  op  duplicature  of  the  membrane  which  forms 
the  surface  contiguous  to  it.  Sometimes  it  is  circu- 
lar, with  an  aperture  in  the  centre.  Sometimes  it 
has  a resemblance  to  the  crescent,  the  aperture  be- 
ing at  the  upper  part  of  it.  The  hymen  has  fre- 
quently been  found  without  a perforation,  and  has 
therefore  prevented  the  discharge  of  the  menstrual 
evacuation.  It  is  generally  ruptured  in  the  first  in- 
tercourse of  the  sexes  ; and  some  small  tubercles, 
which  are  found  on  the  surface  of  the  vagina  near  the 
spot  where  it  was  situated,  are  supposed  to  be  the 
remains  of  it.  These  tubercles  are  called  Car  unci  din 
Mi/rtiformes. 

' SECTION  11. 

Of  the  Vagina. 

The  canal  of  the  vagina,  commencing  at  the  hy- 
men and  the  orifice  of  the  urethra,  is  rather  more 
narrow  at  its  beginning  than  it  is  further  inward.— 
From  this  place  it  extends  backwards  and  upwards, 
and  partakes  in  a small  degree  of  the  curve  of  the 
rectum : while  the  bladder,  which  is  above  it,  and 
rests  upon  it,  increases  the  curvature  of  the  anterior 
part.  It  is  much  larger  in  women  who  have  had 
children  than  in  those  who  have  not. 

The  membrane  which  lines  the  vagina  resembles 
to  a certain  degree,  the  membranes  which  secrete 
mucous  in  different  parts  of  the  body.  Its  surface 
appears  to  consist  of  very  small  papillae  ; and  at  the 
anterior  extremity  of  the  vagina  it  forms  a great 
number  of  rugEe,  which  are  arranged  in  a transverse 
direction,  both  on  the  part  of  the  vagina  connected 
to  the  bladder,  and  on  that  part  which  is  connected  to 
the  rectum,  while  the  lateral  parts  of  the  vagina  are 


204  Corpora  Cavernosa. — Sphincter  Vaginx. 

smooth.  These  rugae  are  most  prominent  in  the  mid- 
tile ; so  that  a raised  line  appears  to  pass  through 
them  at  right  angles.  This  line  extends  from  with- 
out inwards.  The  rugae  on  the  part  next  to  the  blad- 
der are  the  strongest. 

This  arrangement  of  the  surface  of  the  vagina  does 
not  extend  beyond  the  external  half  of  the  canal : on 
the  internal  half  part,  or  that  nearest  the  uterus,  the 

surface  is  smooth. 

The  rugae  are  considerably  diminished  in  women 
who  have  had  children. 

Throughout  this  surface  are  to  be  seen,  in  some 
cases  with  the  naked  eye,  the  orifices  of  mucous  fol- 
licles or  ducts,  which  occasionally  discharge  conside- 
rable quantities  of  mucous. 

Exterior  to  this  lining  membrane  of  the  vagina  is 
a dense  cellular  structure,  which  has  not  yet  been 
completely  investigated  : it  is  of  a lightish  colour,  and 
has  some  resemblance  to  the  texture  of  the  body  of 
the  uterus.  It  is  very  vascular,  and  appears  to  be  of 
a fibrous  structure.  It  may  be  very  much  distended, 
and  seems  to  have  a contractile  power. 

At  the  anterior  extremity  of  the  vagina,  on  each 
side  of  it,  there  is  superadded  to  this,  a cellular,  or 
vascular  substance,  from  eight  lines  to  an  inch  in 
breadth  ; which,  when  cut  into,  resembles  the  cor- 
pora cavernosa,  or  the  corpus  spongiosum  of  the  pe- 
nis. These  bodies  commence  near  the  body  of  the 
clitoris,  and  extend  downwards  on  each  side  of  the 
vagina.  They  have  been  called  Plexus  Eeteformis, 
and  Corpora  Cavernosa  Vaginx , and  are  supposed 
to  be  occasionally  distended  with  blood,  like  the  cli- 
toris and  penis. 

These  corpora  eavernosa  are  covered  by  muscular 
fibres,  which  pass  over  them  on  each  side  from  the 
sphincter  ani  to  the  body  of  the  clitoris ; to  each  of 
which  organs  they  are  attached.  These  fibres  con- 


Unimpregnated  Uterus , 205 

stitute  the  sphincter  vagina  muscle,  and  contract  the 
diameter  of  the  vagina  at  the  place  where  they  are 
situated. 

The  transversus  perinei  muscles  also  exist  in  the 
female.  They  pass  from  the  tuberosities  of  the  ischia, 
and  are*  inserted  into  a dense  whitish  substance  in 
the  perineum,  to  which  the  anterior  extremity  of  the 
sphincter  ani  is  likewise  attached. 

The  vagina  is  in  contact  with  the  rectum  behind  5 
the  bladder  lies  upon  it  and  anterior  to  it.  A small 
portion  of  peritoneum,  to  be  reflected  to  the  rectum, 
is  continued  from  the  uterus  upon  the  posterior  part  • 
of  it.  TJie  lateral  portions  of  it  are  invested  with 
eellular  substance.  The  anterior  extremity  of  the 
uterus,  which  is  called  the  Os  Tinea},  projects  into 

it  from  above. 

* 

SECTION  III. 

Of  the  Uterus , the  Ovaries  and  their  Appendages, 
The  Uterus 

Has  been  compared  to  a pear  with  a long  neck.— 
There  is  of  course  a considerable  difference  between 
the  body  and  neck  ; the  first  being  twice  as  broad  as 
the  last.  Each  of  these  parts  is  somewhat  flattened,* 

In  subjects  of  mature  age,  who  have  never  been 
pregnant,  the  whole  of  the  uterus  is  about  two  inches 
and  a half  in  length,  and  more  than  one  inch  and  a 
half  in  breadth  at  the  broadest  part  of  the  body : it 
is  also  near  an  inch  in  thickness. 

.It  is  generally  larger  than  this  in  women  who 
have  lately  had  children. 

The  uterus  is  situated  in  the  pelvis  between  the 
bladder  and  rectum,  and  is  enclosed  in  a duplicature 
or  fold  of  the  peritoneum,  which  forms  a loose  septum 
that  extends  from  one  side  of  the  pelvis  to  the  other,  ^ 
and  divides  it  into  an  anterior  and  posterior  cham 


2(>o  Ligaments  of  the  Uterus. 

her.  The  posterior  surface  of  this  septum  is  oppo- 
sed to  the  rectum,  and  the  anterior  to  the  bladder. 
The  two  portions  of  this  septum,  which  are  between 
the  uterus  and  the  lateral  parts  of  the  pelvis,  are 
called  the  Broad  Ligaments. 

On  the.  posterior  surface,  the  Ovaries  are, situated 
on  each  side  of  the  uterus,  being  enclosed  by  a pro- 
ct&&of  the  ligament  or  septum.  Above  them,  in  the 
upper  edge  of  the  septum,  are  the  Fallopian  Tubes , 
which  are  ducts  that  commence  at  the  upper  part  of 
the  uterus  on  each  side,  and  proceed,  in  a lateral  di~ 
: *iion  for  some  distance,  when  they  form  an  angle 
and  incline  downwards  to  the  ovaries.  These  ducts 
are  enclosed  between  the  two  lamina  of  the  septum 
for  the  greater  part  of  their  length. 

The  peritoneum,  which  forms  the  septum,  is  re- 
flected from  it,  posteriorly,  to  the  rectum  and  the 
posterior  surface  of  the  pelvis,  and  anteriorly,  to  the 
bladder.  In  its  progress,  in  each  direction,  it  forms 
small  plaits  or  folds ; two  of  which  extend  from  the 
uterus  to  the  rectum  posteriorly,  and  two  more  to  the 
bladder  anteriorly  : these  are  called  the  Anterior 
and  Posterior  Ligaments  of  the  Uterus. 

The  other  ligaments,  which  proceed  more  imme- 
diately from  the  uterus,  are  called  the  Bound  Liga- 
ments. These  arise  from  each  side  of  the  uterus,  at 
a small  distance  before  and  below  the  origins  of  the 
fallopian  tubes,  and  proceed  in  an  oblique  course  to 
the  abdominal  rings.  These  ligaments  are  also  in- 
vested by  the  peritoneum.  They  pass  through  the 
rings  and  soon  terminate. 

In  the  body  of  the  uterus  is  a cavity,  which  ap- 
proaches to  the  triangular  form ; and  from  which  a 
canal  proceeds  through  its  neck.  This  cavity  is  so 
small  that  its  sides  are  almost  in  contact,  and  the  ca- 
nal is  in  proportion  ; so  that  this  organ  is  very  thick 
in  proportion  to  its  bulk. 


Structure  and  Cavity  of  the  Uterus.  20 7 

The  substance  of  which  the  uterus  consists  is  very 
firm  and  dense  : it  is  of  a whitish  colour,  with  a slight 
tinge  of  red.  There  are  many  blood  vessels,  with 
nerves  and  absorbent  vessels,  in  its  texture.  The 
nature  and  structure  of  this  substance  has  not  yet 
been  precisely  ascertained.  It  appears  very  different 
indeed  from  muscle  ; but  the  uterus  occasionally  con- 
tracts, with  great  force,  during  labour.  It  is  not  ren- 
dered thin  by  its  enlargement  during  pregnancy,  and 
the  blood  vessels  in  its  texture  are  greatly  enlarged 
at  that  time. 

Exteriorly,  the  uterus  is  covered  by  the  peritone- 
um, as  ha;?  already  been  mentioned.  Internally  it  is 
lined  with  a delicate  membrane  that  has.  some  resem- 
blance to  those  which  secrete  mucous,  and  is  gener- 
ally of  a whitish  colour,  abounding  with  small  orifi- 
ces that  can  be  seen  with  a magnifying  glass.  This 
membrane  is  so  intimately  connected  to  the  substance 
of  the  uterus  that  some  anatomists  have  supposed  it 
was  merely  the  internal  surface  of  that  substance,  but 
this  opinion  is  now  generally  abandoned.  It  is  sup- 
posed that  the  colour  of  this  membrane  is  more  florid 
about  the  period  of  menstruation. 

The  cavity  of  the  uterus,  as  has  been  observed  be- 
fore, is  triangular  in  form.  When  the  organ  is  in  its 
natural  position,  the  upper  side  of  this  triangle  is 
transverse  with  respect  to  the  body,  and  the  other 
* sides  pass  downwards  and  inwards.  In  each  of  the 
upper  angles  are  the  orifices  of  the  fallopian  tubes, 
which  are  of  such  size  as  to  admit  a hog’s  bristle. 

The  two  lower  lines  of  the  triangle  are  slightly 
curved  outwards  at  their  upper  extremities  ; so  that 
the  upper  angles  of  the  triangle  project  outwards,, 
and  the  orifices  of  the  fallopian  tubes  are  nearer  to 
the  external  surface  than  they  otherwise  would  be.  ’ 

The  lower  angle  of  the  cavity  of  the  uterus  is  oc-' 


208  Structure  and  Cavity  of  the  Uterus . 

cupied  by  the  orifice  of  the  canal,  which  passes 
through  the  neck  of  the  organ  ; this  orifice  is  from 
three  to  four  lines  in  diameter.  The  canal  is  about 
an  inch,  in  length,  and  is  rather  wider  in  the  middle 
than  at  either  end.  On  the  anterior  and  posterior 
portions  of  its  surface  are  many  small  ridges  which 
have  an  arborescent  arrangement,  one  large  ridge 
passing  internally  from  the  commencement  of  the 
canal,  from  which  a number  of  other  ridges  go  off  in 
a transverse  direction.  These  ridges  extend  nearly 
the  whole  length  of  the  canal.  In  the  grooves,  be- 
tween the  ridges,  are  the  orifices  of  many  mucous 
ducts.  There  are  also  on  this  surface  a tnumber  of 
transparent  bodies  of  a round  form,  equal  in  bulk  to 
a middle  sized  grain  of  sand  the  nature  and  use  of 
which  is  unknown.  They  have  been  called  Qvida 
JYabothi,  after  a physiologist,  who  published  some 
speculations  respecting  their  use,  about  the  com- 
mencement of  the  last  century. 

The  canal  of  the  neck  of  the  uterus  is  very  dif- 
ferent from  other  ducts,  for  it  seems  to  he  a part  of 
the  cavity  to  which  it  leads,  and  when  the  cavity  of 
the  uterus  becomes  enlarged  in  the  progress  of  preg- 
nancy, this  canal  is  gradually  converted  into  a part  of 
that  cavity. 

The  lower  extremity  of  the  neck  of  the  uterus  is 
irreglarly  convex  and  tumid.  The  orifice  of  the 
canal  in  it  is  oval,  and  so  situated  that  it  divides  the 
convex  surface  of  the  neck  into  two  portions,  which 
are  called  the  Lips.  The  anterior  or  upper  portion 
is  thicker  than  the  other. 

This  extremity  of  the  uterus  protrudes  into  the  va- 
gina, and  is  commonly  called  Os  Tincse . As  the  an- 
terior portion  or  lip  is  larger  and  more  tumid  than 
‘the  posterior,  the  vagina  extends  further  beyond  the 
os  tincse  on  the  posterior  part  than  on  the  anterior., 


Fallopian  Tubes. —Round  Ligaments  209 
The  Fallopian  Tubes 

Are  two  canals,  from  four  to  five  inches  in  length? 
which  proceed  between  the  lamina  of  the  broad  liga- 
ments, from  the  upper  angles  of  the  uterus,  in  a 
transverse  direction,  to  some  distance  from  the  ute- 
rus, when  they  form  an  angle,  and  take  a direction 
downwards  towards  the  ovaries. 

They  are  formed,  for  a considerable  part  of  their 
extent,  by  a substance  which  resembles  that  of  which 
the  uterus  consists,  and  are  lined  by  a membrane 
continued  from  the  internal  membrane  of  the  uterus* 
Their  extremities  appear  to  be  composed  of  mem- 
brane, which  is  rendered  florid  by  the  blood  vessels 
in  its  texture*  At  the  commencement  their  diameters 
are  extremely  small ; but  they  enlarge  in  their  pro- 
gress. This  enlargement  is  gradual  for  the  first  half, 
and  afterwards  sudden ; the  enlarged  part  is  more 
membranous  than  the  small  part,  and  has  a bright 
red  colour.  The  large  extremity  is  loose  in  the  ca- 
vity of  the  pelvis,  and  is  not  invested  by  the  lamina 
of  the  broad  ligaments.  Near  the  termination  the 
diameter  is  often  contracted  ; after  which  the  mem- 
brane which  forms  the  tube  expands  into  an  open 
mouth,  the  margin  of  which  consists  of  fringed  pro- 
cesses : this  margin  is  also  oblique,  as  respects  the 
axis  of  the  tube  ; and  the  different  fringed  processes 
are  not  all  of  the  same!  length  ; but  the  longest  are 
in  the  middle,  and  the  others  regularly  diminish  on 
each  side  of  them : these  processes  constitute  the 
Fimbriae  of  the  fallopian  tubes. 

The  internal  surface  of  the  large  extremities  of 
these  tubes  is  extremely  vascular ; and  there  are 
some  longitudinal  fibres  of  a red  colour  to  be  seen 
on  it. 

The  Round  Ligaments , 

Which  have  already  been  mentioned,  are  cords  of 

Vjpffc.  n,  27 


21 U 


* Structure  of  the  Ovaries . 

a fibrous  structure,  with  many  blood  vessels  in  them. 
They  arise  from  the  uterus  below  the  origin  of  the 
fallopian  tubes,  and  proceed  under  the  anterior  la- 
mina of  the  broad  ligaments  to  the  abdominal  rings, 
through  which  they  pass;  and  then  the  fibres  and 
vessels  are  expanded  upon  the  contiguous  cellular  I 
substance. 

The  Ovaries 

Are  two  bodies  of  a flattened  oval  form  ; one  of 
which  is  situated  on  each  side  of  the  uterus  on  the 
posterior  surface  of  the  broad  ligament,  and  invested 
completely  by  a process  of  the  posterior  fa  men, 
which  forms  a coat,  and  also  a ligament  for  it.  The 
size  of  this  organ  varies  in  different  subjects,  but  in 
a majority  of  those  who  are  about  the  age  of  matu- 
rity it  is  between  ten  and  twelve  lines  in  length.  It 
is  connected  to  the  uterus  by  a small  ligament,  or 
bundle  of  fibres  of  the  same  structure  with  the  round 
ligaments,  which  is  not  more  than  two  lines  in  dia- 
meter, and  is  included  between  the  lamina  of  the 
broad  ligament. 

The  process  of  the  broad-  ligament  forms  an  exter- 
nal coat  to  the  ovary  ; within  this  is  the  proper  coat 
of  the  organ,  which  is  a firm  membrane.  This  mem- 
brane is  so  firmly  connected  to  the  substance  of  the 
ovary  which  it  encloses,  that  it  cannot  be  easily  se- 
parated from  it.  The  ovary  is  of  a whitish  colour 
and  soft  texture,  and  has  many  blood  vessels.  Ia 
virgins  of  mature  age  it  contains  from  fen  to  twenty 
vesicles,  formed  of  a delicate  membrane,  filled  with 
a transparent  coagulable  fluid.  Some  of  these  vesi- 
cles are  situated  so  near  to  the  surface  of  the  ovary 
that  they  are  prominent  on  its  surface;  others  are 
near  the  centre.  They  are  very  different  in  size ; 
the  largest  being  between  two  and  three  lines  ir 


Arteries  of  the  Uterus „ 21 1 

diameter,  and  others  not  more  than  one-third  of  that 
size. 

In  women  who  have  had  children,  or  in  whom 
conception  has  taken  place,  some  of  these  vesicles 
are  removed ; and  in  their  place  a cicatrix  is  found. 

It  has  been  ascertained,  that  during  the  sexual 
intercourse  with  males,  one  of  these  vesicles,  which 
was  protuberant  on  the  surface,  is  often  ruptured, 
and  a cavity  is  found.  A cicatrix -is  soon  formed, 
where  the  membrane  was  ruptured  ; and  in  the  place 
occupied  by  the  vesicle  there  is  a yellow  substance 
denominated  Coi'pus  Luteum.  This  corpus  luteum 
generally  continues  until  the  middle  of  pregnancy: 
it  often- remains  during  that  state,  and  for  some  time 
after  delivery,  but  it  gradually  vanishes.  The  cica- 
trization continues  during  life. 

In  many  cases  these  cicatrices  correspond  with  the 
number  of  conceptions  which  have  taken  place  ; but 
they  often,  exceed  the  number  of  conceptions,  and 
they  have  been  found  in  cases  where  conception  has 
not  been  known  to  have  taken  place. 

In  very  old  subjects,  where  conception  has  never 
taken  place,  the  vesicles  are  either  entirely  removed, 
or  small  dense  tubercles  only  remain  in  their  place. 

The  Arteries 

Of  the  uterus  are  derived  from  two  very  different 
sources ; viz.  from  the  spermatic  and  from  the  hy- 
pogastric arteries. 

The  spermatic  arteries,  instead  of  passing  directly 
down  to  the  abdominal  ring,  proceed  between  the 
lamina  of  the  broad  ligament,  and  send  branches  to 
the  ovaries,  which  may  sometimes  be  traced  to  the 
vesicles.  They  also  send  branches  to  the  fallopian 
tubes  and  to  the  uterus.  Those  which  are  on  the 
opposite  sides  of  the  uterus  anastomose  with  each 
other,  and  also  with  the  branches  of  the  hypogastric 


3X2  .Veins  of  the  Uterus . 

arteries.  There  are  also  branches  of  these  arteries 
in  the  round  ligaments  which  accompany  them  to 
their  termination  outside  of  the  abdominal  ring. 

The  principal  arteries  of  the  uterus  are  those  de- 
rived from  the  hypogastric,  which  sends  to  each  side 
of  it  a considerable  branch,  called  the  Uterine.  This 
vessel  leaves  the  hypogastric  very  near  the  origin  of 
the  internal  pudic,  and  proceeds  to  the  cervix  of  the 
uterus : it  passes  between  the  lamina  of  the  broad  li- 
gaments,  and  sends  branches  to  the  edge  of  the  ute- 
rus, which  penetrate  its  texture.  The  branches  which 
are  in  the  texture  of  the  uterus,  are  very  small  in- 
deed. in  young  subjects.  In  women  who  have  had 
children  they  are  considerably  larger;  but  during 
pregnancy  they  gradually  enlarge  with  the  growth  of 
the  uterus,  and  become  very  considerable.  These 
arteries  observe  a serpentine  and  peculiarly  tortu- 
ous course.  Those  on  the  opposite  sides  anastomose 
with  each  other. 

The  Veins 

Of  the  uterus,  like  the  arteries,  form  spermatic 
and  uterine  trunks.  The  Spermatic  Vein  is  much 
larger  than  the  artery.  It  ramifies  as  in  males,  and 
forms  a very  large  plexus,  w hich  constitutes  the  cor- 
pus pampiniforme.  Many  of  the  veins  which  form 
this  body,  originate  near  the  ovary:  a considerable 
jjumber  also  come  from  the  fallopian  tubes  and  the 
uterus.  The  spermatic  vein  and  its  branches  are 
greatly  enlarged  indeed  during  pregnancy ; and  it  is 
said  that  they  are  enlarged  the  same  way  during  the 
menstrual  discharge. 

The  most  imporant  veins  of  the  uterus  are  the 
branches  of  the  Uterine  Veins.  They  are  extremely 
numerous,  and  form  a plexus  on  the  side  of  the  ute- 
rus ; from  which  two  or  more  uterine  veins  proceed 
in  the  course  of  the  artery,  and  join  the  hypogastric 


Lymphatics. —Bladder  and  Urethra.  213 

These  veins  also  are  greatly  enlarged  during  preg- 
nancy. 

The  Lymphatic  Vessels 

Of  the  uterus,  and  its  appendages,  are  very  nu- 
merous. In  the  unimpregnated  state  they  are  small ; 
but,  during  pregnancy,  they  increase  greatly.  They 
proceed  from  the  uterus  in  very  different  directions. 
Some  that  accompany  the  round  ligaments  go  to  the 
lymphatic  glands  of  the  groin.  Others  which  take 
the  course  of  the  uterine  blood  vessels  pass  to  glands 
in  the  pelvis,  and  a third  set  follows  the  spermatic 
arteries  and  veins  to  the  glands  on  the  loins. 

The  JYerves 

Of  the  ovaries  are  derived  from  the  renal  plexus, 
and  those  of  the  uterus  and  vagina  from  the  hypo- 
gastric plexus,  or  the  lower  portions  of  the  sympa- 
thetic, and  the  third  and  fourth  sacral  nerves, 

SECTION  IV. 

Of  the  Bladder  and  Urethra. 

The  situation  of  the  Bladder , as  respects  the  sym 
phisis  pubis,  is  nearly  alike  in  both  sexes ; but  that 
part  of  it  which  is  immediately  behind  the  insertion 
of  the  ureters  is  rather  lower  in  males  than  in  fe- 
males. The  bottom  of  the  bladder  rests  upon  the 
upper  part  of  the  vagina,  a thin  stratum  of  cellular 
substance  only  intervening:  when  that  viscus  is  dis- 
tended it  forms  a tumour,  which  compresses  the  va- 
gina. 

The  ureters  are  inserted,  and  the  urethra  commen- 
ces in  the  same  part  of  the  bladder,  in  both  sexes. 

The  length  of  the  Urethra  is  between  one  and 
two  inches.  When  the  body  is  in  a direct  position, 
it  is  nearly  horizontal;  but  it  is  slightly  curved?  with 


314  General  Change  in  (he  Gravid  Uterus. 

its  convexity  downwards.  It  is  immediately  above 
the  vagina,  and  it  passes  below  the  body  of  the  cli- 
toris. The  external  orifice  of  it  is  rather  more  than 
an  inch  within  the  gians  or  head  of  the  clitoris. 
This  orifice  is  somewhat  prominent  in  the  vagina. 

In  the  internal  or  lining  membrane  of  the  urethra 
there  are  many  orifices  of  mucous  follicles,  and  also 
longitudinal  wrinkles,  as  in  the  urethra  of  males. 
The  diameter  of  the  female  urethra  and  its  orifice  in 
the  bladder  are  greater  than  they  are  in  the  male. 
For  this  reason  it  has  been  supposed,  that  women  are 
less  liable  to  calculus  of  the  bladder  than  men.*  • 

The  urethra  is  intimately  connected  with  the  ex- 
ternal coat  of  the  vagina,  and  between  them  there  is 
a spongy  cellular  substance  which  makes  the  fough 
surface  of  the  vagina  prominent ; so  that  the  urethra 
has  been  supposed,  although  erroneously,  to  be  in- 
vested with  the  prostate.  It  is  capable  of  great  ar- 
tificial dilatation.  - 

Of  the  Changes  induced  in  the  Uterus  in  the  pro- 
gress of  Pregnancy . 

The  alteration  which  takes  place  in  the  size  of  the 
uterus  during  pregnancy  is  truly  great.  About  the 
conclusion  of  that  period,  instead  of  the  small  body 
above  described,  which  is  almost  solid,  the  uterus 
forms  an  immense  sac,  which  extends  from  the  ter- 
mination of  the  vagina  in  the  pelvis,  into  the  epigas- 
tric region  ; and  from  one  jside  of  the  abdomen  to  the 
other ; preserving,  however  an  ovoid  figure. 

This  change  is  so  gradual  at  first,  that  the  uterus 
does  not  extend  beyond  the  cavity  of  the  pelvis  be- 
fore the  third  month,  although  at  the  end  of  the  se- 
venth month  it  is  very  near  the  epigastric  region. 

For  the  first  six  months  the  body  of  the  uterus 

* It  has  however  been  asserted  that  they  are  also  less  liable  to  calculi  m 
the  kidneys. 


General  Observations, 


215 


appears  principally  concerned  in  the  enlargement : 
after  this  the  cervix  begins  to  change,  and  is  gradu- 
ally altered  so  as  to  compose  a portion  of  the  sac, 
rather  of  less  thicknes  than  the  rest  of  the  uterus  ; 
the  mouth  being  ultimately  an  aperture  in  a part 
which  is  much  thinner  than  the  other  portions  of  the 
organ. 

The  change  which  takes  place  in  the  texture  of 
some  of  the  appendages  of  the  uterus  is  very  import- 
ant. 

The  Broad  Ligaments , which  seem  particularly 
calculated  to  favour  the  extension  of  the  uterus,  are 
necessarily  altered  by  the  change  in  the ’size  of  that 
organ,  but  not  entirely  done  away.  The  portion  of 
peritoneum  of  which  they  are  formed  must  be  very 
much  enlarged  with  the  growth  of  the  uterus,  as  it 
continues  to  cover  it.  The  Round  Ligaments  are 
much  elongated ; and  they  observe  a more  straight 
course  to  the  abdominal  ring.  The  Fallopian  Tubes 
are  enlarged ; and  instead  of  passing  off  laterally 
from  the  uterus,  they  now  proceed  downwards  by 
the  side  of  it.  The  Ovaries  appear  rather  larger 
and  more  spongy : their  relative  situation  is  necessa- 
rily lower. 

The  change  in  the  Uterus  itself  is  particularly  in- 
teresting. The  great  increase  of  its  size  is  not  at- 
tended with  any  considerable  diminution  of  thick- 
ness in  its  substance ; nor  are  the  arteries  much  less 
convoluted  than  before  pregnancy , as  might  have 
been  expected.  They  are  greatly  enlarged  in  diam 
eter,  and  the  orifices  of  the  exhalent  vessels  on  the 
internal  surface  of  the  uterus  are  much  more  percep- 
tible. 

The  veins  are  much  more  enlarged  than  the  arte- 
ries, and  in  some  places  appear  more  than  half  an 
inch  in  diameter.  They  are  not  regularly  cylindri- 


216  Peculiarity  of  the  Female  Hottentots. 

cal,  but  rather  flat.  They  anastomose  so  as  to  form 
an  irregular  net  work. 

The  uterus  appears  much  more  fibrous  and  mus- 
cular in  the  gravid  than  in  the  unimpregnated  state. 
The  contractile  power  of  the  gravid  uterus  is  not  only 
proved  by  the  expulsion  of  its  contents,  but  also  by 
very  vigorous  contractions,  which  are  occasionally 
observed  by  accoucheurs. 

Although  the  general  effects  which  result  from  the  par- 
ticular conditions  of  the  uterus  in  pregnancy,  men- 
struation, &c.  evince  that  the  influence  of  this  organ 
upon  the  whole  system  is  very  great,  yet  it  seems  pro- 
bable'that  the  sexual  peculiarities  of  females  are  espe- 
cially dependent  upon  the  ovaria. 

This  sentiment  is  confirmed  by  an  account  of  a wo- 
man in  whom  the  ovaria  were  deficient,  which  is  pub- 
lished in  the  London  Philosophical  Transactions  for 
1805,  by  Mr.  C.  Pears.  The  subject  lived  to  the  age 
of  twenty-nine  years.  She  ceased  to  grow  after  the 
age  of  ten  years,  and  therefore  was  hot  more  than  four 
feet  six  inches  in  height : her  breadth  across  the  hips 
was  but  nine  inches,  although  the  breadth  of  tne 
shoulders  was  fourteen.  Her  breasts  and  nipples  ne- 
ver enlarged  more  than  they  are  in  the  male  subject. 
There  was  no  hair  on  the  pubes,  nor  were  there  any 
indications  of  puberty  in  mind  or  body.  She  never 
menstruated.  At  the  age  of  twenty -nine  she  died  of  a 
complaint  in  the  breast,  attended  with  convulsions. — 
The  uterus  and  os  tine®  were  found  not  increased 
beyond  their  usual  size  during  infancy.  The  cavity 
of  the  uterus  was  of  the  common  shape,  but  its  coats 
were  membranous.  The  Fallopian  Tubes  were  per- 
vious. “ The  Ovaria  were,  so  indistinct  that  they  ra- 
ther showed  the  rudiments  which  ought  to  have  form- 
ed them , than  any  part  of  the  natural  structure .V 
Another  case,  which  confirms  the  aforesaid  sentiment, 
is  related  in  one  of  the  French  periodical  publications.. 

It  has  been  long  known  that  a race  of  savages  near 
the  Cape  of  Good  Hope  were  distinguished  trom  the 
generality  of  their  Species  by  a*  peculiarity  about  the 
pudendum.  An  account  of  this  structure  has  been 


Peculiarities  in  the  Abdomen  of  the  Fcetus  217" 

given  with  some  precision  by  Messrs.  Peron  and  Le- 
sueur,  in  a paper  which  was  read  to  the  National  Insti- 
tute of  France.  It  is  a flap  or  apron,  four  inches  in 
length,  which  is  united  to  the  external  labia  near  their 
upper  angle,  and  hangs  down  before  the  clitoris  and 
the  external  orifice  of  the  parts  of  generation.  It  is 
divided  below  into  two  lobes,  which  covers  the  orifice. 
It  is  formed  by  a soft  distensible  skin,  free  from  hair, 
which  is  occasionally  corrugated  like  the  scrotum,  and 
is  rather  more  florid  than  the  ordinary  cutis.s 

The  Abdomen  of  the  Fcetus. 

The  difference  between  the  foetus  and  the  adult, 
in  the  cavity  of  the  abdomen,  is  very  conspicuous  at 
the  first  view. 

The  Liver  in  the  foetus  is  so  large  that  it  occupies 
a very  considerable  part  of  the  abdomen.  Its  left 
lobe,  which  is  larger  in  proportion  than  the  right, 
extends  far  into  the  left  hypochondriac  region. 

The  Bladder  of  urine , when  filled,  extends  from 
the  cavity  of  the  pelvis  a considerable  distance  to- 
wards the  umbilicus : so  that  the  greatest  part  of  it 
is  in  the  cavity  of  the  abdomen.  A ligament  of  a 
conical  figure  extends  from  the  centre  of  the  upper 
part  of  the  bladder  to  the  umbilicus ; with  an  artery 
on  each  side  of  it,  which  is  soon  to  be  described. 
This  ligament,  which  is  in  the  situation  of  the  ura- 
chus of  the  fcetus  of  quadrupeds,  is  hollow,  and  thus 
frequently  forms  a canal,  which  has  a very  small 
diameter,  that  communicates  with  the  bladder  by  an 
aperture  still  smaller,  and  continues  a short  distance 
from  the  bladder  towards  the  umbilicus.  In  a few 
rare  instances  this  canal  has  extended  to  the  umbili- 
cus, so  that  urine  has  been  discharged  through  it,  but 
the  ligament  is  commonly  solid  there. 

* This  paper  has  not  yet  been  published  by  the  Institute,  but  it  is  refer- 
red to  by  M.  Cuvier  in  his  Lemons  d’Anatomie  Comparee,  voL  v.  page 
124.— Messrs.  Peron  and  Lesueur  were  naturalists  who  accompanied  captain 
Baudin  in  his  voyage  of  discover}-;  the  latter  has  been  for  some  years  re- 
sident in  Philadelphia, 

VOL-v  IT, 


18 


218  Descent  of  the  Testicle  in  the  Foetus . 

The  Stomach  appears  to  be  more  curved  in  the 
foetus  than  in  the  adult. 

The  Great  Intestine  does  not  extend  sufficiently 
far,  beyond  the  insertion  of  the  ileon,  to  form  the 
cfecum  completely. 

The  Glandalse  JRenales  are  much  larger  in  pro- 
portion in  the  foetus  than  in  the  adult.  The  colour 
of  the  fluid  they  contain  is  more  florid. 

The  Kidneys  are  lobulated. 

The  Testicles  in  the  foetus  are  found  above  the 
pelvis,  in  the  lumbar  region,  behind  the  peritoneum, 
until  two  months  before  birth.  Thus  situated,  their 
blood  vessels  and  nerves  proceed  from  sources  which 
are  near  them ; but  the  vas  deferens,  being  connected 
to  the  vesiculac  seminales  by  one  extremity,  is  neces- 
sarily in  a very  different  situation  from  what  it  is  in 
the  adult:  it  proceeds  from  the  testicle  downwards  to 
the  neck  of  the  bladder. — While  each  testicle  is  in 
this  situation,  it  is  connected  with  a substance  or  liga- 
ment, called  Gubernaculwn , of  a conical  or  pyrami- 
dical  form,  attached  to  its  lower  end,  and  extends 
from  it  to  the  abdominal  ring.  This  substance  is 
vascular,  and  of  a fibrous  texture:  its  large  extremity 
adheres  to  the  testicle,  its  lower  and  small  extremity 
passes  through  the  abdominal  ring,  and  appears  to 
terminate  in  the  cellular  substance  exterior  to  that 
opening,  like  the  round  ligament  in  females.  The 
Gubernaculum,  as  well  as  the  testicle,  is  behind  the 
peritoneum  ; and  the  peritoneum  adheres  to  each  of 
them  more  firmly  than  it  does  to  any  of  the  surround- 
ing parts.  It  seems  that,  by  the  contraction  of  the 
Gubernaculum , the  testicle  is  moved  down  from  its 
original  situation  to  the  abdominal  ring,  and  through 
the  abdominal  ring  into  the  scrotum.  The  perito- 
neum, which  adheres  firmly  to  the  gubernaculum  and 
testicle,  and  is  loosely  connected  to  the  other  parts, 
yields  to  this  operation ; and  \yhen  the  testicle  has 


Descent  of  the  Testicle  in  the  Fcetus . 219 

arrived  near  the  abdominal  ring,  a portion  of  the  pe- 
ritoneum is  protruded  a little  way  before  it  into  the 
scrotum  ; forming  a cavity  like  the  finger  of  a glove. 
The  testicle  passes  down  behind  this  process  of  the 
peritoneum,  and  is  covered  by  it  as  it  was  in  the  ab- 
domen. Although  it  appears  protruded  into  the  ca- 
vity, it  is  exterior  to  it,  and  behind  it ; and  the  ves- 
sels, &c.  which  belong  to  the  testicle  are  also  ex- 
terior  to  it. 

The  cavity  formed  in  the  scrotum,  by  this  process 
of  the  peritoneum,  necessarily  communicates  with  the 
cavity  of  the  abdomen  at  its  formation  ; but  very  soon 
after  the  testicle  has  descended  into  the  scrotum,  the 
upper  part  of  this  cavity  is  closed  up,  while  the  low- 
er part  of  the  process  continues  unchanged,  and  con- 
stitutes the  Tunica  Vaginalis  Testis.  In  some  in- 
stances the  upper  part  of  this  process  does  not  close 
up,  and  the  communication  with  the  cavity  of  the 
abdomen  continues.  The  descent  of  the  intestine 
into  the  cavity  thus  circumstanced,  constitutes  that 
species  of  Hernia  which  is  denominated  Congenital.* 

The  most  important  peculiarities  in  the  abdomen 
of  the  foetus  are  those  connected  with  the  circulation 
of  the  blood. 

The  internal  iliac  or  hypogastric  arteries  are  larger 
than  the  external  iliacs.  Their  main  trunks  are 

* These  interesting  circumstances  respecting  the  original  situation  of 
the  testicle,  and  its  descent  into  the  scrotum,  were  discovered  and  elu- 
cidated by  Haller,  Hunter,  Pott,  Camper,  and  several  other  very  respect- 
able anatomists  and  surgeons.  There  is,  however,  a difference  of  opin- 
ion, between  some  of  them,  as  to  the  time  when  the  testicle  leaves  the 
abdomen.  Haller  thought  the  testicles  were  seldom  in  the  scrotum  at 
birth.  Hunter  and  Camper  found  them  so  generally. 

It  has  been  suggested  that  there  are  some  national  peculiarities  in  this  re- 
spect ; that  amongst  the  Hungarians,  for  example,  the  testicles  often  re- 
main above  the  abdominal  ring  until  near  the  age  of  puberty. 

The  student  will  find  an  interesting  description  of  the  situation  of  the 
testis,  and  its  descent,  in  the  foetus,  in  the  “ Observations  o.n  certain  parts 
of  the  Animal  Economy, 51  by  John  Hunter, 


Umbilical  Vessels. 


;i2U 

continued  on  each  side  of  the  bladder  to  its  fundus  t 
and  proceed  from  it,  with  the  ligament,  to  the  umbi- 
licus ; when  they  pass  out  of  the  abdomen  to  go  along 
the  umbilical  cord  to  the  placenta.  These  arteries 
are  now  denominated  the  Umbilical,  and  are  very 
considerable  in  size.  After  birth,  as  there  is  no  cir- 
culation in  them,  they  soon  begin  to  change  : the  ca- 
vity of  them  is  gradually  obliterated,  and  they  are 
converted  into  ligaments.  They  are  exterior  to  the 
peritoneum,  and  contained  in  a duplicature  of  it. 

A vein  also  called  the  Umbilical,  which  is  much 
larger  in  diameter  than  both  of  the  arteries,  returns 
from  the  placenta  along  the  cord,  and  enters  the  ca- 
vity of  the  abdomen  at  the  umbilicus.  It  proceeds 
thence,  exterior  to  the  peritoneum,  but  in  a duplica- 
ture of  it  called  the  Falciform  Ligament , to  the 
liver,  and  enters  that  viscus  at  the  great  fissure  ; 
along  which  it  passes  to  the  left  branch  of  the  sinus 
of  the  vena  portarum,  into  which  it  opens  and  dis- 
charges the  blood  which  flows  through  it  from  the 
placenta.  It  opens  on  the  anterior  side  of  the  branch 
of  the  vena  portarum,  and  from  the  posterior  side  of 
the  branch,  opposite  to  this  opening,  proceeds  a duct 
or  canal,  which  opens  into  the  left  hepatic  vein  near 
its  junction  with  the  vena  cava.  This  communicating 
vessel  is  called  the  Ductus,  or  Canalis  Venosus  ; to 
distinguish  it  from  the  duct  which  passes  from  the 
pulmonary  artery  to  the  aorta,  and  is  called  Ductus , 
or  Canalis  Arteriosus.  This  venous  duct  carries 
some  of  the  blood  of  the  umbilical  vein  directly  to 
the  vena  cava  ; but  it  is  much  smaller  than  the  um- 
bilical vein,  and  of  course  a considerable  quantity  of 
the  blood  which  passes  through  the  umbilical  vein 
must  pass  through  the  liver,  by  the  vena  portarum, 
before  it  can  enter  the  cava. 

In  some  foetal  subjects,  if  a probe  of  sufficient 


Object  of  the  Circulation  in  the  Placenta.  221 

length  be  introduced  within  the  umbilical  vein  and 
pushed  forwards,  it  will  pass  to  the  heart  without 
much  difficulty  or  opposition,  as  if  it  proceeded  along 
one  continued  tube,  although  it  really  passes  from 
the  umbilical  vein  across  the  branch  of  the  vena  por- 
tarum,  and  then  through  the  ductus  venosus,  and 
through  a portion  of  the  left  hepatic  vein,  into  the 
inferior  vena  cava. 

If  the  umbilical  vein  be  injected  with  a composi- 
tion, which  will  be  firm  when  cool,  it  appears  to 
terminate  in  a rounded  end,  which  is  situated  in  the 
transverse  fissure  of  the  liver  : the  sinus  of  the  vena 
portarum,  into  which  this  vein  enters,  appears  like 
two  branches  going  off,  one  from  each  side  of  it,  and 
the  ductus  venosus  like  a branch  continuing  in  the 
direction  of  the  main  trunk  of  the  umbilical  vein. 

The  umbilical  vein,  in  its  progress  through  the 
fissure  of  the  liver,  before  it  arrives  at  the  sinus  of 
the  vena  portarum,  sends  off  a considerable  number 
of  branches  to  each  of  the  lobes  of  that  organ,  but 
more  to  the  left  than  to  the  right  lobe. 

After  birth,  when  blood  ceases  to  flow  through  the 
umbilical  vein,  it  is  gradually  converted  into  a liga- 
ment ; and  the  venous  duet  is  also  converted  into  a 
ligament  in  the  same  manner.  The  vena  portarum, 
which  before  appeared  very  small,  when  compared 
with  the  umbilical  vein,  now  brings  all  the  blood 
which  fills  its  great  sinus,  and  increases  considerably 
in  size. 

It  has  been  ascertained  by  anatomical  investiga- 
tion, that  the  umbilical  arteries  above  mentioned, 
after  ramifying  minutely  in  the  placenta,  communi- 
cate with  the  minute  branches  of  the  umbilical  vein  ; 
and  it  is  probable  that  the  whole  blood  carried  to  the 
placenta  by  these  arteries,  returns  by  the  umbilical 
vein  to  the  foetus. 

It  is  dearly  proved  by  the  effects  of  pressure  on 


222  Object  of  the  Circulation  in  the  Placenta. 

the  umbilical  cord,  in  cases  of  delivery  by  the  feet, 
as  well  as  by  other  similar  circumstances*  that  this 
circulation  cannot 'be  suspended  for  any  length  of 
time  without  destroying  the  life  of  the  foetus.'  From 
these  circumstances,  and  from  the  florid  colour 
which  the  blood  acquires  by  circulating  in  the  pla- 
centa, it  seems  probable  that  the  object  of  the  circu- 
lation through  that  organ  is  somewhat  analogous  to 
the  object  of  the  pulmonary  circulation  through  the 
lungs  of  adults.*  * 

* During  the  first  four  months  of  pregnancy  a very  small  vesicle,  which 
does  not  exceed  the  size  of  apea,  is  found  between  the  chorion  and  the  amnios, 
near  the  insertion  of  the  umbilical  cord  into  the  placenta.  It  is  connected 
to  the  fetus  by  an  artery  and  a vein,  which  pass  from  the  abdomen  through 
the  umbilicus,  and  proceeding  along  the  cord  to  the  placenta,  continue 
from  it  to  the  vesicle.  The  artery  arises  from  the  mesenteric,  and  the 
veii^  is  united  to  the  mesenteric  branch  of  the  vena  portarum.  It  is  proba- 
ble that  these  vessels  commonly  exist  no  longer  than  the  vesicle,  viz. 
about  four  months  ; but  they  have  been  seen  by  Haller  fujd-Chaussier  at 
the  termination  of  pregnancy.  They  are  called  Omphat&iiHesenteric  -ves- 
sels. The  vesicle  is  denominated  the  Umbilical  Vesicle. 

This  inexplicable  structure  is  delineated  in  Hunter’s  Anatomy  of  the 
Gravid  Uterus,  plate  xxxiii.  figures  v.  and  vi. ; in  the  Academical  Annota- 
tions of  Albums,  first  book,  plate  i.  figure  xii.;  and  also  in  the  leones  Em- 
bryonum  Humanortun  of  SoemmeriDg,  figure  & 


SYSTEM  OF  ANATOMY. 

PART  IX. 


OF  THE  BLOOD  VESSELS. 

The  blood  vessels  are  flexible  tubes,  of  a peculiar 
texture,  through  which  blood  passes  from  the  heart 
to  the  different  parts  of  the  body,  and  returns  again 
from  these  parts  to  the  heart.  They  are  to  be  found, 
in  varying  proportions,  in  almost  every  part  of  the 
body,  and  seem  to  enter  into  its  texture. 

The  tubes  which  carry  blood  from  the  heart,  are 
more  substantial  and  more  elastic  than  those  through 
which  it  returns  to  the  heart.  They  are  generally 
found  empty  after  death ; and,  therefore,  were  called 
Arteries  by  the  ancient  anatomists,  who  supposed 
that  they  carried  air,  and  not  blood. 

The  tubes  which  return  the  blood  to  the  heart  are 
denominated  Veins . They  are  less  substantial  and 
less  elastic  than  arteries,  and  are  generally  fall  of 
blood  in  the  dead  subject. 

There  are  two  great  arteries,  from  which  all  the 
Other  arterial  vessels  of  the  body  are  derived.  They 
are  very  justly  compared  to  the  trunks  of  trees,  and 
the  smaller  vessels  to  their  branches.  One  of  these 
great  arteries,  called  the  Aorta,  carries  blood  to  eve- 
ry part  of  the  body.  The  other  great  vessel,  called 
the  Pulmonary  Artery , carries  blood  exclusively  to 
the  lungs. 


S24  The  Blood  vessels  in  general . 

The  veins  which  correspond  to  the  branches  of  the 
Aorta,  unite  to  each  other,  so  as  to  form  two  great 
trunks  that  proceed  to  the  heart.  One  of  these 
trunks,  coming  from  the  superior  parts  of  the  body, 
is  called  the  Superior,  or  Descending  Vena  Cava. 
The  other,  which  comes  from  the  lower  parts  of  the 
body,  is  called  the  Inferior,  or  Ascending  Vena 
Cava. 

The  veins  which  correspond  with  the  branches  of 
the  Pulmonary  Artery,  and  return  to  the  heart  the 
blood  of  the  lungs,  are  four  in  number : two  of  them 
proceeding  from  each  lung.  They  are  called  Pul- 
monary Veins. 

In  many  of  the  veins  there  are  valves,  which  pre- 
vent the  blood  they  contain  from  moving  towards  the 
surface  and  extremities  of  the  body,  but  allow  it  to 
pass  towards  the  heart  without  impediment. 

From  the  construction  of  the  cavities  of  the  heart, 
and  the  position  of  the  valves  which  are  in  them  ; as 
well  as  the  situation  of  the  valves  at  the  commence- 
ment of  the  great  arteries,  and  the  above  mentioned 
valves  of  the  veins,  it  is  evident,  that  when  the  blood 
circulates,  it  must  move  from  the  heart,  through  the 
aorta  and  its  branches,  to  the  different  parts  of  the 
body,  and  return  from  these  parts  through  the  venae 
cavae,  to  the  heart ; that,  when  deposited  in  the  heart 
by  the  venae  cavae,  it  must  proceed  through  the  pul- 
monary artery  to  the  lungs,  and  return  from  the 
lungs  through  the  pulmonary  veins  to  the  heart,  in 
order  to  pass  again  from  that  organ  into  the  aorta. 

It  is  also  certain,  that  the  blood  is  forced  from  the 
heart  into  the  arteries,  by  the  contraction  of  the  mus- 
cular fibres  of  which  the  heart  is  composed ; and  that 
the  blood  vessels  likewise  perform  a part  in  the  cir- 
culation, they  propelling  the  blood  which  is  thus 
thrown  into  them  : but  their  action  appears  to  depend 
upon  causes  of  a complex  nature. 


CHAPTER  I. 


OF  THE  GENERAL  STRUCTURE  AND  ARRANGEMENT 
OF  THE  BLOOD  VESSELS, 

SECTION  r. 

Of  the  Arteries. 

The  arteries  are  so  much  concerned  in  the  im- 
portant function  of  the  circulation  of  the  blood,  that 
every  circumstance  connected  with  them  is  very  in- 
teresting. 

They  are  composed  of  coats  or  tunics,  which  are 
very  elastic  and  strong,  and  which  are  also  very  thick. 
In  consequence  of  the  firmness  of  their  coats,  they 
continue  open,  after  their  contents  are  discharged, 
like  hard  tubes.  They  submit  to  great  dilatation, 
and  elongation,  when  fluids  are  forced  into  them,  and 
return  to  their  former  dimensions  when  the  distend- 
ing cause  is  withdrawn.  This  elasticity  is  particu- 
larly subservient  to  the  circulation  of  the  blood. ' It 
admits  the  artery  to  distend  readily,  and  receive  the 
biood  which  is  thrown  into  it  by  the  contraction  of 
the  heart.  It  also  produces  the  contraction  of  the 
artery;  which  takes  place  as  soon  as  the  action  of  the 
heart  ceases ; and  this  contraction  of  the  artery  neces- 
sarily forces  the  blood  forward,  as  the  valves  at  its 
orifice  prevent  it  from  returning  to  the  heart. 

The  motion  of  the  artery,  which  is  so  easily  per- 
ceived by  the  touch,  and  in  many  instances  also  by 
the  eye,  is  completely  explained  by  the  discharge  of 
blood  into  the  arterv  from  the  heart,  and  by  the 
VOL.il.  29  ' 


226 


Structure  of  the  Arteries. 

elasticity  of  the  vessel,  by  which  it  re-acts  upon  the 
blood.  In  some  cases  it  is  not  simply  the  diameter 
of  the  artery  which  is  enlarged,  but  a portion  of  the 
vessel  is  elongated;  and  this  elongation,  by  pro- 
ducing a curvature  of  it,  renders  its  motion  more 
visible. 

In  the  aorta,  and  probably  in  its  large  branches, 
Elasticity  seems  to  be  the  principal  cause  of  the  con- 
tinuance of  the  motion  which  is  originally  given  to 
the  blood  by  the  heart.  But  there  are  many  circum- 
stances connected  with  the  smaller  vessels,  which 
evinee  that  they  exert  a power  which  is  very  differ- 
ent indeed  from  elasticity.  Thus  the  application  of 
local  stimulants  or  rubefacients,  and  of  heat,  is  fol- 
lowed by  an  increase  of  motion  in  the  arteries  of  the 
parts  to  which  they  are  applied.  Neither  of  these 
causes  could  produce  their  effect  by  the  influence  of 
elasticity : but  the  effect  of  these  and  other  similar 
causes  is  uniformly  produced ; and  a power  of  inde- 
pendent motion,  or  Irritability , is  thus  proved  to 
exist  in  these  vessels,  and  seems  essentially  necessa- 
ry to  the  circulation  of  the  blood. 

The  Structure  of  the  Arteries 

Is,  therefore,  a subject  of  importance;  and  has  re- 
ceived a considerable  degree  of  attention  from  anato- 
mists. 

They  are  composed  of  a dense  elastic  substance, 
of  a whitish  colour.  Their  external  surface  is  rough, 
and  intimately  connected  with  the  cellular  membrane, 
which  every  where  surrounds  it  in  varying  quanti- 
ties. Internally,  they  are  lined  with  a thin  mem- 
brane, which  is  very  smooth  and  flexible,  and  is  also 
very  elastic.  The  substance  which  composes  the 
artery,  and  is  situated  between  the  cellular  invest- 
ment and  the  internal  membrane,  consists  of  fibres, 
which  are  nearly,  though  not  completely,  circular, 


227 


/ Structure  of  the  Arteries . 

but  so  arranged  as  to  constitute  a cylinder.  These 
fibres  may  be  separated  from  each  other  so.  as  to 
form  lamina,  which  have  been  considered  as  differ- 
ent coats  of  the  arteries  ,•  but  there  is  no  arrange- 
ment of  them  which  composes  regular  distinct  strata. 
The  coats  of  arteries  may,  therefore,  be  separated 
into  a greater  or  smaller  number  of  lamina,  accord- 
ing to  the  thickness  of  these  lamina. 

The  fibres  which  compose  these  lamina  appear  to 
be  united  to  each  other  in  a way  which  readily  al- 
lows of  their  separation,  at  the  same  time  that  they 
form  a firm  texture.  Although  arteries  thus  appear 
essentially  different  from  muscles  in  their  hardness 
and  their  elasticity,  as  well  as  in  their  general  tex- 
ture, they  are  considered,  by  a great  majority  of 
anatomists,  as  partaking  more  or  less  of  a muscular 
structure. 

In  the  human  subject  their  structure  is  very  diffi- 
cult of  demonstration,  and  great  differences  exist  in 
the  accouuts  which  are  given  of  it,  even  by  anato- 
mists who  agree  in  the  general  sentiment  that  the 
arteries  are  muscular. 

Thus  Haller  believed  that  muscular  fibres  were 
most  abundant  in  the  large  arteries,  while  J.  Hunter 
thought  the  reverse. 

Hunter  appears  to  have  investigated  this  subject 
with  great  attention,  and  supposed  the  muscular 
substance,  in  the  composition  of  arteries,  to  be  inte- 
rior, and  the  elastic  matter  exterior ; that  in  large 
arteries  this  muscular  substance  is  very  small  in 
quantity,  and  gradually  increases  in  proportion  as 
the  artery  diminishes  in  size.  He  however  observes, 
that  he  never  could  discover  the  direction  of  the 
muscular  fibres* 

When  the  great  talents  of  Mr.  Hunter  as  an 

' Treatise  on  the  Blond,  &c,  Voi  I,  p.  ITS.  Bradford’s  edition 


228  Question? expecting  the  muscularity  of  Arteries . 

anatomist,  are  considered,  this  circumstance  cannot 
fail  to  excite  a belief  that  the  existence  of  these  ' 
fibres  is  not  certain  : and  if  to  this  be  added  the  fact, 
that  even  the  red  coloured  substance  of  the  arteries 
is  elastic,  and  in  that  respect  different  from  muscu- 
lar substance,  the  reasons  for  doubting  must  be  in- 
creased. 

Bichat  appears  to  have  entertained  very  strong 
doubts  on  the  subject ; but  he  stands  almost  alone  ; 
for  a large  number  both  of  the  preceding  and  cotem- 
porary anatomists,  seem  to  have  adopted  the  senti- 
ment, that  the  arteries  have  a muscular  structure. 

The  student  of  anatomy  can  very  easily  examine 
this  subject  himself,  by  separating  the  coats  of  arte- 
ries into  different  lamina  ; and  by  viewing  the  edges 
of  the  transverse  and  longitudinal  sections  of  those 
vessels.  While  thus  engaged  with  this  question,  he 
will  read  with  great  advantage  what  has  been  writ- 
ten upon  it  by  Mr.  Hunter,  in  his  Treatise  on  the 
Blood,  &c.  See  chapter  second,  section  3.  Bichat 
ought  also  to  be  read  upon  this  subject,  which  he 
has  discussed  in  his  Anatomie  Generate — -Systeme 
Vasculaire  a Sang  Rogue , article  Troisieme,  &c.  and 
also  in  his  Traite  des  Membranes , article  Sixieine. 

The  belief  of  the  irritability  of  arteries  does  not 
however,  rest  upon  the  appearance  of  their  fibres. 

1.  It  is  asserted  by  very  respectable  authors,* 
that  they  have  been  made  to  contract  by  the  appli- 
cation of  mechanical  and  of  chemical  irritation,  and 
also  of  the  electric  and  galvanic  power. 

2.  A partial  or  local  action  of  arteries  is  often 
produced  by  the  local  application  of  heat  and  rube- 
facients, as  has  been  already  observed. 

* See  Soemmering  on  the  structure  of  the  Human  Body,  Vol.  IV.  Ger- 
man edition.  Dr.  Jones, on  the  Process  employed  by  nature  for  suppressing 
Hemorrhage,  &c. 


Proofs  of  the  Irritability  of  the  Jlrteries, 

3.  Arterial  action  is  often  suspended  in  a particu- 
lar part  by  the  application  of  cold.  It  has  also  been 
observed  that  the  arteries  have  for  a short  time  ceas- 
ed to  pulsate  in  cases  of  extreme  contusion  and  lace- 
ration of  the  limbs.* 

4.  When  arteries  are  divided  transversely  in  living 
animals,  they  often  contract  so  as  to  close  completely 
the  orifice  made  by  the.  division. 

5.  In  a horse  bled  to  death,  it  was  ascertained  by 
Mr.  Hunter,  that  the  transverse  diameter  of  the  ar- 
teries was  diminished  to  a degree  that  could  not  be 
explained  by  their  elasticity.  He  also  found  that, 
after  death,  the  arteries,  especially  those  of  the 
smaller  size,  are  generally  in  a state  of  contraction, 
which  is  greater  than  can  be  explained  by  their  elas- 
ticity: for  if  they  are  distended  mechanically,  they 
do  not  contract  again  to  their  former  size,  but  conti- 
nue of  a larger  diameter  than  they  were  before  the 
distention;  although  their  elasticity  may  act  so  as  to 
restore  a very  considerable  degree  of  the  contraction 
observed  at  death. 

The  contraction,  which  is  thus  done  away  by  dis- 
tention, Mr.  Hunter  supposed  to  have  been  produced 
by  muscular  fibres  : for,  if  it  had  been  dependent  on 
elasticity,  it  must  have  re-appeared  when  the  distend- 
ing power  was  withdrawn. 

It  therefore  seems  certain,  that  the  arteries  have  a 
power  of  contraction  'different  from  that  which  de- 
pends upon  elasticity ; but  whether  this  depends 
upon  muscular  fibres  superadded  to  them,  or  upon 
an  irritable  quality  in  the  ordinary  elastic  fibres  of 
blood  vessels,  is  a question  which  is  not  perhaps 
completely  decided. 

* This  local  suspension  of  arterial  motion  by  cold,  &c.  applied  locally, 
is  very  difficult  to  explain;  as  the'  action  of  the  heart  and  the  elasticity  of 
the  arteries  appear  sufficient  to  account  for  the  pulsation  of  the  large  ar- 
teries. 


230  General  Observations  on ■ the  Arteries. 

The  motion  of  the  blood  in  the  arteries  appears  to 
depend, 

1st,  Upon  the  impulse  given  to  it  by  the  action  of 
the  heart. 

2dly,  Upon  the  elasticity  of  the  arteries,  in  conse- 
quence of  which  they  first  give  way  to  the  blood 
impelled  into  them,  and  then  re-act  upon  it;  and 

3dly,  Upon  the  power  of  contraction  in  the  arte- 
ries, or  their  irritability. 

In  the  larger  arteries  the  blood  seems  to  move  as 
it  would  through  an  inanimate  elastic  tube,  in  conse- 
quence of  the  impulse  given  by  the  heart,  and  kept 
up  by  the  arteries  themselves.  In  the  smaller  ves- 
sels it  seems  probable  that  the  motion  of  the  blood 
depends  in  a considerable  degree  upon  the  contrac- 
tion which  arises  from  their  irritability. 

The  obvious  effect  of  the  elasticity  of  the  arteries 
is  to  resist  distention  and  elongation,  and  to  contract 
the  artery  to  its  natural  state,  when  the  distending 
or  elongating  cause  ceases  to  act.  But  it  must  also 
resist  the  contraction  induced  by  the  muscular  fibres, 
and  restore  the  artery  to  its  natural  size  when  the 
muscular  fibres  cease  to  act  after  contracting  it,  as 
has  been  observed  by  Mr.  Hunter. 

It  seems  probable  that  all  the  fibres  of  which  the 
artery  consists  are  nearly  but  not  completely  circular, 
for  it  is  not  certain  that  there  are  any  longitudinal 
fibres  in  the  structure  of  an  artery. 

The  internal  coat  of  these  vessels  is  very  smooth, 
but  extremely  dense  and  firm;  and  seems  to  be  ren- 
dered moist  and  flexible  by  an  exudation  on  its  sur- 
face. It  adheres  very  closely  to  the  contiguous  fibres 
of  the  coat  exterior  to  it,  but  may  be  very  readily 
peeled  off  from  them.  It  is  of  a whitish  colour, 
and,  like  the  fibrous  structure  of  the  artery,  is  very 
elastic.  Like  that  substance  also  it  is  easily  torn  or 
broken,  and  when  ligatures  have  been  applied  to 


General  Observations  on  the  Arteries . 231 

arteries,  it  has  often  been  observed  that  the  fibrous 
structure  and  the  internal  coat  have  been  separated 
while  this  external  cellular  coat  has  remained  en- 
tire. 

The  arteries  are  supplied  with  their  proper  blood 
vessels  and  lymphatics.  It  is  to  be  observed,  that 
the  blood  vessels  are  not  derived  from  the  artery  on 
which  they  run,  but  from  the  contiguous  vessels. 

These  vessels  have  nerves  also,  which  are  rather 
small  in  size,  when  compared  with  those  which  go  to 
other  parts. 

Arteries  appear  to  have  a cylindrical  form,  for  no 
.diminution  of  diameter  is  observable  in  those  portions 
of  them  which  send  off*  no  ramifications. 

When  an  artery  ramifies  the  area  of  the  differ- 
ent branches  exceeds  considerably  that  of  the  main 
trunk.  Upon  this  principle  the  aorta  and  its  branches 
have  been  compared  to  a cone,  the  basis  of  which 
is  formed  by  the  branches,  and  the  apex  by  the 
trunk.* 

The  transverse  section  of  an  artery  is  circular. 

There  are  no  valves  in  the  arteries,  except  those 
of  the  orifices  of  the  aorta  and  the  pulmonary  artery, 
at  the  heart.  The  valves  of  the  pulmonary  artery 
have  been  described  in  the  51st  page  of  this  volume, 
and  those  of  the  aorta  have  an  exact  resemblance  to 
them,  but  are  rather  larger. 

The  course  of  the  arteries  throughout  the  body  is 
obviously  calculated  to  prevent  their  exposure  to 
pressure,  or  to  great  extension  from  the  flexure  of  the 
articulations  by  which  they  pass.  With  this  view 
they  sometimes  proceed  in  a winding  direction ; and 
when  they  pass  over  parts  which  are  subject  to  great 
distention  or  enlargement,  as  the  cheeks,  they  often 

* According  to  Brassiere  the  relation  of  the  branches  of  the  aorta  to  its 
trunk  is  as  25  to  16;  Helvetius  reckons  the  orifice  of  the  aorta  in  compa^ 
visori  ■with  its  branches  as  64  to  71.  Lassus.— Es. 


I 


232  General  Observations  on  the  Arteries, 

meander;  and,  therefore,  their  length  may  be  in- 
creased by  straightening,  without  stretching  them. 

Their  course  appears  sometimes  to  have  been 
calculated  to  lessen  the  force  of  the  blood,  as  is  the 
case  with  the  Internal  Carotid  and  the  Vertebral  ar- 
teries. 

In  the  trunk  of  the  body  the  branches  of  arteries 
generally  form  obtuse  angles  with  the  trunks  from 
which  they  proceed.  In  the  limbs  these  angles  are 
acute. 

The  communication  of  arteries  with  each  other  is 
termed  Anastomosis.  In  some  instances,  two  branches 
which  proceed  in  a course  nearly  similar,  unite, 
with  an  acute  angle,  and  form  one  common  trunk. — 
Sometimes,  a transverse  branch  runs  from  one  to  the 
other,  so  as  to  form  a right  angle  with  each.  In 
other  cases,  the  two  anastomosing  branches  form  an 
arch,  or  portion  of  a circle,  from  which  many  branches 
go  off. 

By  successive  ramifications,  arteries  gradually  di- 
minish in  size,  until  they  are  finally  extremely  small. 

The  smallest  arteries  do  not  carry  red  blood,  their 
diameters  being  smaller  than  those  of  the  red  parti- 
cles of  that  fluid,  the  serous  or  aqueous  part  of  the 
blood  can,  therefore,  only  pass  through  them. 

Many  of  the  arteries  which  carry  red  blood,  and 
of  the  last  mentioned  serous  arteries  terminate  in 
veins,  which  are  in  some  respects,  a continuation  of 
the  tube  reflected  backwards.# 

* Malpighi  and  Leeuwenhoek  declare,  that  by  the  aid  of  a microscope, 
they  have  seen  arteries  terminating  in  the  veins.  Haller  advances  for- 
mally his  own  experience  in  support  of  his  assertion.  Other  anatomists 
have  seen,  that  in  blowing  into  an  artery,  the  air  passed  into  the  corres- 
ponding veins.  Nevertheless,  Duverney  and  some  others  say,  that  a 
particular  substance  is  interposed  between  the  extremities  of  these  ves- 
sels. Ruyseh  in  his  Thesauras  Anatomic'us,  VI.  No.  73,  says,  in  repletione 
arteriarum,  replentur  et  plurimum  quosque  vense,  et  vice  versa,  ita  ut  im- 
possible videatur  precise  dicere  quomodo  res  .se  habeat.  Discours  sur 
i’Anat — Ep.  ~ ' • 


General  Observations  on  the  Ferns.  233 

They  likewise  terminate  in  exhalent  vessels,  which 
open  upon  the  external  surface,  and  upon  the  various 
internal  surfaces  of  the  body.  The  secretory  vessels 
of  glands  are  likewise  the  termination  of  many  arte- 
ries. 

SECTION  II. 

Of  the  Feins. 

These  tubes,  which  return  to  the  heart  the  blood 
carried  from  it  by  the  arteries,  are  more  numerous 
than  the  arteries,  and  often  are  larger  in  diameter. 

They  generally  accompany  the  arteries,  and  very 
often  two  veins  are  found  with  one  artery. 

In  addition  to  these  last  mentioned  veins,  which 
may  be  called  deep-seated , there  are  many  subcuta- 
neous veins  which  appear  on  almost  every  part  of 
the  surface  of  the  body. 

The  capacity  of  all  the  veins  is  therefore  much 
greater  than  that  of  all  the  arteries. 

Those  subcutaneous  veins,  which  are  of  consider- 
able size,  communicate  very  freely  with  each  other, 
and  also  with  the  deep-seated  veins. 

The  trunks  of  the  veins,  in  those  places  where  no 
branches  go  off,  are  generally  cylindrical.  There 
are,  however,  some  exceptions,  in  which  these  ves- 
sels are  irregularly  dilated,  as  sometimes  happens  in 
the  case  of  the  internal  jugular  vein.  It  is  how- 
ever, not  easy  to  determine  from  the  appearance  of 
veins  injected  after  death,  respecting  their  situation 
during  life,  as  their  coats  are  very  yielding ; and  it 
is  very  probable  that  they  are,  therefore,  preterna- 
turally  dilated  by  the  injection. 

Veins , directly  or  indirectly,  originate  from  the 
termination  of  arteries : but  they  do  not  pulsate  as 
the  arteries  do,  because  the  impulse  given  to  the 

Vgl.  EE.  30 


234 


Coats  of  Veins. 

blood  by  the  heart  is  very  much  diminished  in  con- 
sequence of  the  great  diminution  of  the  size  of  the 
vessels  through  which  the  blood  has  passed. 

In  some  cases,  however,  when  blood  flows  from 
an  opened  vein ; the  extent  of  its  projection  is  alter- 
nately increased  and  diminished,  in  quick  succes- 
sion, as  if  it  were  influenced  by  the  pulsation  of  the 
heart. 

The  Coats  of  Veins  differ  considerably  from  those 
of  Arteries, — for  they  are  thinner , and  so  much  less 
firm,  that  veins,  unlike  arteries,  collapse  when  they 
are  empty. 

They  Consist  of  a dense  elastic  substance,  the 
fibres  of  which  are  much  less  distinct  than  those  of 
arteries,  but  some  of  them  are  to  be  seen  in  a longi- 
tudinal direction.  These  fibres  can  be  made  to  con- 
tract by  local  irritation  ; for  if  a vein  be  laid  bare 
in  a living  animal,  and  then  punctured,  it  will  often 
contract  so  as  to  diminish  its  diameter  very  consi- 
derably, although  no  blood  shall  have  escaped  from 
the  puuctures. 

Next  to  the  elastic  substance  is  the  internal  coat, 
which  is  smooth  and  polished.  It  is  separated  from 
the  substance  exterior  to  it  with  difficulty,  although 
it  may  be  taken  from  it  very  easily  in  the  vena  cava. 

This  internal  coat  is  more  ostensible  than  the  in- 
ternal coat  of  arteries,  and  is  not,  like  the  latter,  dis- 
posed to  ossification.  It  is  frequently  so  arranged 
as  to  form  valves,  which  are  plaits  or  folds,  of  a se- 
milunar form,  that  project  from  the  surfaces  into  the 
cavities  of  these  vessels.* 

Two  of  these  valves  are  generally  placed  opposite 

The  valves  of  the  veins  were  first  described  by  Charles  Etienne  of  Pa- 
ris in  1546.  In  1547,  Amatus,  a Portuguese,  saw  at  Ferrara  those  at  the 
mouth  of  the  vena  azygos.  Sylvius  of  Paris  announced  them  about  the 
same  time  in  the  jugular,  brachial  and  crural  veins.  Fabricus  ab  Acjua- 
osndente  claims  the  discovery  for  himself  in  1574  Lassus. — Ei?- 


Colour  of  the  Blood  in  the  / 'inns,  235 

to  each  other ; and,  when  raised  up,  they  form  a sep- 
tum in  the  cylindrical  cavity  of  the  vessel.  The  sep- 
tum, thus  composed,  is  concave  towards  the  heart. 

The  valves  have  a great  effect  in  preventing  the 
contents  of  the  veins  from  moving  in  a retrograde 
course : they,  therefore  necessarily  modify  the  effects 
of  lateral  pressure,  in  such  a manner,  that  it  propels 
the  blood  forward,  or  to  the  heart. 

These  valves  are  generally  found  in  the  veins  of 
the  muscular  parts  of  the  body,  especially  in  those  of 
the  extremities.  They  are  not  found  in  those  veins 
which  are  in  the  cavities  of  the  body,  nor  in  the  in- 
ternal jugulars. — They  are  placed  at  unequal  dis- 
tances from  each  other. 

The  coats  of  the  veins  are  somewhat  transparent ; 
and,  therefore,  those  veins  which  are  subcutaneous 
have  a bluish  aspect,  which  is  derived  from  the  co- 
lour of  the  blood  they  contain. 

The  colour  of  the  blood  in  the  veins  is  different 
from  that  in  the  arteries,  being  of  a darker  red. 

The  situation  and  arrangement  of  the  large  trunks 
of  veins  is  much  alike  in  different  subjects ; but  the 
branches,  especially  those  which  are  subcutaneous, 
are  very  variable  in  their  situations. 


CHAPTER  II. 


A PARTICULAR  ACCOUNT  OF  THE  DISTRIBUTION  OF  THE 
ARTERIES. 

SECTION  r. 

Of  the  AORTA,* 

Or  the  Great  Trunk  of  the  Arterial  System „ 

When  the  heart  ia  in  its  natural  position,  the  right 
ventricle  is  nearly  anterior  to  the  left,  and,  therefore, 
the  aorta,  where  it  originates  from  the  left  ventri- 
cle, is  behind  the  pulmonary  artery,  and  covered  by 
it.  Its  first  direction  is  so  oblique  towards  the  right 
side  of  the  body,  that  it  crosses  the  pulmonary  artery 
behind,  and  appears  on  the  right  side  of  it.  It  has 
scarcely  assumed  this  position  before  its  course  alters, 
for  it  then  proceeds  obliquely  backwards,  and  to  the 
left;  so  as  to  form  a large  curve  or  arch,  which  ex- 
tends to  the  left  of  the  spine. 

The  position  of  this  curve  or  arch  is  so  oblique, 
with  respect  to  the  body,  that  the  cord  or  diameter 
of  it,  if  it  were  extended  anteriorly  and  posteriorly, 
would  strike  the  cartilage  of  the  second  or  third  right 
rib  about  the  middle  of  its  length,  and  the  left  rib 
near  the  head.  In  consequence  of  this  position  of 
the  curve,  the  aorta  crosses  over  the  right  branch 
of  the  pulmonary  artery,  and  the  left  branch  of  the 
windpipe : and  assumes  a situation,  in  front,  and  to 
the  left  of  the  third  dorsal  vertebra:  from  this  situa- 
tion it  proceeds  downwards;  in  front,  but  rather  on 


* This  name  was  given  by  A ristotle.— Et>. 


Situation  ofthe  Aorta  in  the  Thorax  fy  Abdomen.  237 

the  left  side  of  the  spine,  and  in  contact  with  that 
column. 

The  aorta,  as  well  as  the  Pulmonary  Artery , 
for  a small  distance  from  the  heart,  is  invested  by 
the  pericardium ; and,  when  that  sac  is  opened,  ap- 
pears to  be  contained  in  it. 

After  crossing  the  right  branch  of  the  Pulmonary 
Artery , a ligament  is  inserted  into  it,  which  proceeds 
from  the  main  trunk  of  the  Pulmonary  artery  at  its 
division : this  ligament  was  the  Canalis  Arteriosus 
in  the  foetus. 

As  the  aorta  proceeds  down  the  spine,  it  is  si- 
tuated between  ,the  two  lamina  of  the  mediastinum, 
and  in  contact  with  the  left  lamen,  through  which  it 
mav  be  seen.  It  descends  between  the  crura  of  the 
diaphragm,  in  a vacuity  which  is  sufficiently  large 
to  admit  of  its  passage  without  pressure  from  the 
surrounding  parts,  and  is  still  in  contact  with  the 
anterior  surface  of  the  spine,  but  rather  te)  the  left  of 
• the  middle  of  it.  It  continues  this  course  along  the 
spine  until  it  arrives  at  the  cartilaginous  substance 
between  the  fourth  and  fifth  lumbar  vertebra,  when 
it  divides  into  two  great  branches  of  equal  size, 
which  form  an  acute  angle  with  each  other.  These 
are  denominated  the  common,  or  primitive  iliac 
Arteries. 

From  the  aorta  in  this  course  are  sent  off  the  ar- 
teries which  are  distributed  to  all  the  parts  of  the 
body  for  their  nourishment  and  animation.  ^ 

From  the  curve  proceed  the  great  branches  which 
supply  the  heart,  the  head,  the  upper  extremities, 
and  part  of  the  thorax.  Between  the  curve  and  the 
great  primitive  iliac  arteries,  the  aorta  sends  off 
those  branches  which  supply  the  viscera  contained 
in  the  cavities  of  the  thorax  and  abdomen,*  and  part 

* It  ought  to  be  observed  here,  that  the  viscera  iu  the  lower  part  of  the 
pelvis  receive  some  branches  from  the  internal  iliac  arteries. 


238  Origin  of  the  Subclavian  and  Carotid  Arteries . 

of  the  trunk  of  the  body.  The  great  ILIAC  branches 
of  the  AORTA  are  divided  into  smaller  arteries, 
which  supply  the  whole  of  the  lower  extremities  and 
some  of  the  viscera  of  the  pelvis. 

SECTION  II. 

Of  the  Branches  which  go  off  from  the  (well  of  the- 
AORTA, 

The  proper  arteries  of  the  heart,  denominated  co- 
ronary arteries,  proceed  from  the  aorta  so 
near  to  the  heart  that  their  orifices  are  covered  by 
the  semilunar  valves,  vrhen  those  valves  are  pressed 
against  the  sides  of  the  artery.  These  arteries  have 
been  described  in  the  account  of  the  heart.— -See 
p.  50. 

The  arteries  of  the  head  and  of  the  upper  extremi- 
ties proceed  from  the  upper  part  of  the  curve  in  the 
following  manner. 

A large  trunk,  called  arteria  innominata,  goes 
off  first.  This  is  more  than  sixteen  lines  in  length, 
when  it  divides  into  two  branches : one  of  which 
supplies  the  right  side  of  the  head,  and  is  denomi- 
nated the  right  carotid  : the  other  proceeds  to  the 
right  arm,  and  from  its  course  under  the  clavicle,  is 
called,  at  first,  the  right  subclavian.  Almost  in 
contact  with  the  first  trunk,  another  artery  goes  off, 
which  proceeds  to  the  left  side  of  the  head,  and  is 
called  the  left  carotid.  Very  near  to  this,  arises 
the  third  artery,  which  proceeds  to  the  left  arm,  and  is 
denominated  the  left  subclavian.  From  these  great 
branches  originate  the  blood  vessels,  which  are  spent 
upon  the  head  and  neck  and  the  upper  extremities. 

As  these  arteries  arise  from  the  curve  of  the 
aorta,  they  are  situated  obliquely  with  respect  to 
each  other.  The  arteria  innominata  is  not  only 


Situation  of  the  Common  Carotid  Arteries.  239 

to  the  right,  bat  it  is  also  anterior  to  the  two  others : 
and  the  left  subclavian  is  posterior,  as  well  as  to 
the  left  of  the  left  carotid  and  the  arteria  in- 

NOMINATA. 

THE  CAROTID  ARTERIES. 

The  two  carotid  arteries  above  mentioned  have 
been  denominated  common  carotids,  to  distinguish 
them  from  their  first  ramifications  which  are  called 
internal  and  external  carotids. 

THE  COMMON  CAROTIDS 

Proceed  towards  the  head  on  each  side  of  the  trachea : 
at  first  they  diverge,  but  they  soon  become  nearly 
parallel  to  each  other,  and  continue  so  until  they  have 
ascended  as  high  as  the  upper  edge  of  the  thyroid 
cartilage,  when  they  divide  into  the  internal  and 

EXTERNAL  CAROTIDS. 

These  arteries  are  at  first  very  near  each  other, 
and  rather  in  front  of  the  trachea ; they  gradually 
diverge  and  pass  backwards  and  outwards  on  the 
sides  of  it,  and  of  the  oesophagus,  until  they  have  ar» 
rived  at  the  larynx.  In  the  lower  part  of  the  neck 
they  are  covered  by  the  sterno  mastoidei,  the  sterno 
hyoidei,  and  thyroidei,  as  well  as  by  the  platysma 
myoidei  muscles.  Above,  their  situation  is  more  su- 
perficial ; and  they  are  immediately  under  the  pla- 
tysma myoides. 

On  the  inside,  they  are  very  near  the  trachea  and 
larynx,  and  the  oesophagus ; on  the  outside,  and  ra- 
ther anterior  to  them,  are  the  internal  jugular  veins; 
and  behind,  on  each  side,  are  two  important  nerves 
called  the  intercostal  and  the  par  vagum . These 
blood  vessels  and  nerves  are  surrounded  by  absor- 
bent vessels. 


£40  External  Carotid  Artery. 

The  common  carotid  artbries  send  off  no 
branches  from  their  origin  to  their  bifurcation  ; and 
they  appear  to  preserve  the  same  diameter  through- 
out their  whole  extent.  In  some  few  instances  the 
right  carotid  has  been  found  larger  than  the  left. 
The  external  and  internal  branches  into  which  they 
divide,  are  nearly  equal  in  the  adult ; but  it  is  sup- 
posed that  the  internal  is  the  largest  during  infancy. 
The  relative  position  of  these  branches  is  also  differ- 
ent at  the  commencement  from  what  it  is  afterwards. 
The  internal  carotid  forms  a curve  which  pro- 
jects outwardly,  so  as  to  be  exterior  to  the  exter- 
nal carotid,  while  this  last  proceeds  upwards,  and 
rather  backwards. 

THE  EXTERNAL  CAROTID  ARTERY 

May  be  considered  as  extending  from  its  commence- 
ment, which  is  on  a line  with  the  superior  margin  of 
the  thyroid  cartilage,  to  the  neck  of  the  condyle  of 
the  lower  jaw,  or  near  it. 

At  first  it  is  superficial ; but  as  it  proceeds  up- 
wards it  becomes  deep-seated  ; and  passing  under 
the  digastric  and  stylo-hyoidei  muscles,  and  the  ninth 
pair  of  nerves,  is  covered  by  the  Parotid  Gland. 
After  this,  it  again  becomes  superficial ; for  the  tem- 
poral artery,  which  may  be  regarded  as  the  contin- 
uation of  the  external  carotid,  passes  over  the  zygo- 
matic process  of  the  temporal  bone. 

As  the  external  carotid  supplies  with' blood  the 
upper  part  of  the  neck  and  throat,  the  exterior  of 
the  head  and  face,  and  the  inside  of  the  mouth  and 
nose ; its  branches  must  necessarily  be  numerous, 
and  must  pass  in  very  various  directions. 

Thus,  soon  after  its  commencement,  it  sends  off,  in 
an  anterior  direction,  three  large  branches;  viz.  to  the 
upper  part  of  the  neck,  to  the  parts  within  the  lower 
jaw,  and  to  the  cheeks  and  lips.  These  are  deno- 


External  Carotid  and  its  Branches.  241 

minated,  the  superior  thyroid,  the  sublingual, 
and  the  facial.  It  then  sends  off  to  the  back  of  the 
head  one  which  is  called  the  occipital  ; and,  as  it 
proceeds  upwards  near  the  condyle  of  the  lower  jaw, 
another  which  passes  internallv,  behind  the  jaw,  to 
the  deep-seated  parts  in  that  direction.  After  this, 
it  forms  the  temporal  artery,  which  supplies  the  fore- 
head and  central  parts  of  the  cranium.  Besides  these 
larger  branches,  the  external  carotid  sends  of  two 
which  are  smaller ; one  from  near  the  origin  of  the 
sublingual  artery,  which  is  spent  principally  upon  the 
pharynx  and  fauces,  and  is  called  the  inferior  pha- 
ryngeal : and  another,  while  it  is  involved  with  the 
parotid  gland,  which  goes  to  the  ear;  and  is  there- 
fore called  posterior  auris. 

These  arteries  are  distributed  in  the  following 
manner : 

1.  The  superior  thyroid  branch 

Comes  off  very  near  the  root  of  the  external  carotid, 
and  sometimes  from  the  common  trunk  ; it  runs  ob- 
liquely downwards  and  forwards,  in  a meandering’ 
course,  to  the  thyroid  gland,  where  it  is  speut.  Dur- 
ing this  course  it  sends  off  one  branch  to  the  parts 
contiguous  to  the  os  hyoides  ; another  to  the  neigh- 
bourhood of  the  larynx  : and  a third  branch,  which 
may  be  termed  laryngeal , that  passes  with  a small 
nerve  derived  from  the  laryngeal  branch  of  the  par 
vagum,  either  between  the  os  hyoides  and  thyroid 
cartilage,  or  the  thyroid  and  cricoid  cartilages,  to 
the  interior  muscles  of  the  larynx ; and  finally  re- 
turns again  to  terminate  externally. 

While  in  the  thyroid  gland  this  artery  anastomo- 
ses with  the  inferior  thyroid,  and  also  with  its  fellow 
•on  the  opposite  side., 

VoL,  IX.  31 


242  Brandies  of  the  External  Carotid . 

t.  The  LINGUAL,  or  sublingual  branch, 

Goes  off  above  the  last  mentioned  artery,  and  very 
near  it ; but  in  a very  different  direction,  for  it  runs 
upwards  and  forwards,  to  the  tongue.  In  this  course 
it  crosses  obliquely  the  os  hyoides,  and  is  commonly 
within  the  hyoglossus  muscle.  It  gives  off  branches 
to  the  middle  constrictors  of  the  pharynx,  and  to  the 
muscles  contiguous  to  the  tongue.  It  also  sends  off  a 
branch  which  penetrates  to  the  back  of  ' the  tongue, 
which  is  called,  from  its  situation,  Dorsalis  Linguse. 
^t  the  anterior  margin  of  the  hyoglossus  muscle  it 
divides  into  two  branches,  one  of  which  passes  to  the 
sublingual  gland  and  the  adjacent  parts,  and  is  thence 
called  Sublingual ,*  while  the  other  branch,  thei?am- 
na , passes  by  the  side  of  the  genio  glossus  muscle  to 
the  apex  of  the  tongue. 

3.  The  facial  or  external  maxillary, 

Runs  obliquely  upwards  and  forwards  under  the  ninth 
pair  of  nerves,  the  stylo  hyoideus  muscle  and  the  ten- 
don of  the  digastric,  across  the  lower  jaw  and  cheek, 
towards  the  inner  corner  of  the  eye,  in  a serpentine 
course.  Before  it  crosses  the  jaw  it  sends  off  several 
branches,  viz.  to  the  pharynx,  the  tonsils,  the  inferior 
maxillary  gland  and  the  parts  contiguous  to  it.  It  also 
sends  a branch  towards  the  chin,  which  passes  between 
the  mylo-hyoideus,  the  anterior  belly  of  the  digastric, 
and  the  margin  of  the  lower  jaw : and  some  of  its 
branches  continue  to  the  muscles  of  the  under  lip. 
This  branch  is  called  the  Submental. 

This  artery  then  passes  round  the  basis  or  inferior 
edge  of  the  lower  jaw,  very  near  the  anterior  margin 
of  the  masseter  muscle,  and  is  so  superficial  that  its 
pulsations  can  be  readily  perceived.  After  this  turn, 
its  course  is  obliquely  upwards  and  forwards.  Near 
fhe  basis  of  the  jaw  it  sends  off  a branch  to  the  mas 


Branches  of  the  External  Carotid.  243 

seter,  which  anastomoses  with  small  branches  from 
the  temporal ; and  another  which  passes  superficially 
to  the  under  lip  and  contiguous  parts  of  the  cheeks. 
This  last  is  called  the  Inferior  Labial. 

After  the  artery  has  passed  as  high  as  the  teeth  in 
the  lower  jaw,  it  divides  into  two  branches ; which 
go,  one  to  the  under,  and  the  other  to  the  upper  lip; 
that  to  the  upper  lip  is  largest.  These  branches  are 
called  Coronary. 

The  Coronary  Artery  of  the  lower  lip  passes  under 
the  muscles  called  Depressor  Angtili  Oris,  and  Or- 
bicularis Oris,  into  the  substance  of  the  lip,  and 
anastomoses  with  its  fellow  of  the  opposite  side. 

The  Coronary  Artery  of  the  upper  lip  passes  un- 
der the  zygoinaticus  major  and  the  orbicularis,  and 
very  near  the  margin  of  the  upper  lip  internally.  It 
also  anastomoses  freely  with  its  fellow  on  the  oppo- 
site side.  These  anastomoses  are  frequently  so  con- 
siderable that  the  arteries  on  one  side  can  be  well 
filled  by  injecting  those  of  the  other.  The  coronary 
branches,  as  well  as  the  main  trunk  of  the  facial  ar- 
tery, observe  a serpentine  or  tortuous  course ; in  con- 
sequence of  which  they  admit  of  the  motions  of  the 
cheeks  and  lips,  which  they  would  greatly  impede 
if  they  were  straight. 

from  the  upper  coronary  artery  a branch  conti- 
nues in  the  direction  of  the  main  trunk  of  the  fa- 
cial artery,  by  the  side  of  the  nose,  which  extends 
upwards,  sending  olf  small  branches  in  its  course, 
and  finally  terminates  about  the  internal  angle  of  the 
eye  and  the  forehead. 

4.  The  INFERIOR  PHARYNGEAL 

Is  a very  small  artery ; it  rises  posteriorly  from  the 
external  carotid,  opposite  to  the  origin  of  the  sublin- 
gual, and  passes  upwards  to  the  basis  of  the  era- 


244  Branches  of  the  External  Carotid. 

nium.  In  this  course  it  sends  several  branches  to  the 
pharynx,  and  to  the  deep  seated  parts  immediately 
contiguous. 

It  also  sends  branches  to  the  first  ganglion  of  the 
intercostal  nerve,  to  the  par  vagum,  and  to  the  lym- 
phatic glands  of  the  neck  ; and  finally  it  enters  the 
cavity  of  the  cranium  by  the  posterior  foramen  ia- 

cerum. 

In  some  cases  it  also  sends  a small  branch  through 
the  anterior  foramen  lacerum. 

5.  The  occipital  artery 

Arises  from  the  posterior  side  of  the  external  caro- 
tid, nearly  opposite  to  the  facial,  but  sometimes 
higher  up  ; it  ascends  obliquely,  and  passes  to  the 
back  part  of  the  cranium,  between  the ; transverse 
process  of  the  atlas  and  the  mastoid  process  of  the 
temporal  bone. 

In  this  course  it  passes  over  the  internal  jugular 
vein  and  the  eighth  pair  of  nerves,  and  under  the 
posterior  part  of  the  digastric  muscle ; it  lies  very 
near  to  the  base  of  the  mastoid  process,  and  under 
the  muscles  which  are  inserted  into  it.  After 
emerging  from  these  muscles,  it  runs  superficially 
upon  the  occiput,  dividing  into  branches  which  ex- 
tend to  those  of  the  temporal  artery. 

The  occipital  artery  sends  off  branches  to  the 
muscles  which  are  contiguous  to  it,  and  to  the  glands 
ef  the  neck. 

It  also  gives  off  the  following  branches  : one 
called  the  Meningeal , which  passes  through  the 
posterior  foramen  lacerum  to  the  under  and  back 
part  of  the  dura  mater  : one  to  the  exterior  parts  of 
the  ear  : another  which  passes  downwards,  and  is 
spent  upon  the  complexus,  trachelo  mastoideus,  and 
other  muscles  of  the  neck  : and'  several  smaller  ar- 
teries. 


Branches  of  the  External  Carotid.  245 

The  artery  next  to  be  described,  is  sometimes  sent 
off  by  the  occipital  artery. 

6.  The  posterior  auricular,  or  stylo  mastoid 

ARTERY, 

When  it  arises  from  the  external  carotid,  comes  off 
posteriorly  from  the  artery,  where  it  is  involved  with 
the  parotid  gland,  and  passes  backwards  between  the 
meatus  auditories  externus  and  the  mastoid  process. 
It  then  ascends,  in  a curved  direction,  and  termin- 
ates behind  the  ear. 

In  this  course  it  sends  off  small  branches  to  the 
parotid  gland,  and  to  the  digastric  and  sterno  mas 
toid  muscles.  Sometimes  a distinct  branch,  which 
is  particularly  visible  in  children,  passes  through  an 
aperture  in  the  meatus  auditorius  externus,  and  is 
spent  on  its  internal  surface.  , 

* It  also  sends  off  a branch  which  enters  into  the 
Stylo  Mastoid  Foramen,  and  supplies  small  vessels 
to  the  membrana  tympani  and  the  lining  membrane 
of  the  cavity  of  the  tympanum;  to  the  mastoid  eeiis; 
to  the  muscle  of  the  stapes,  and  to  the  external  semi- 
circular canal.  One  of  these  vessels  anastomoses,  in 
the  upper  and  posterior  part  of  the  cavity  of  the  tym- 
panum, with  a small  twig  derived  from  the  artery  of 
the  dura  mater.  When  it  has  arrived  behind  the 
ear,  the  Posterim'  Auricular  Artery  terminates  upon 
the  external  ear  and  the  parts  contiguous  to  it. 

7.  The  INTERNAL  MAXILLARY  ARTERY^' 

Arises  from  the  external  carotid  under  the  parotid 
gland,  at  a little  distance  below  the  neck  of  the  con- 

* The  general  situation  of  this  artery,  and  the  distribution  of  several  of 
its  most  important  branches,  cannot  be  understood  without  a knowledge  of 
the  bones  through  which  they  pass.  The  student  of  surgery  will  therefore 
derive  benefit  from  a re-examination  of  these  bones,  and  of  the  zygomatic 
fossa,  &c.  when  he  studies  this  artery.  (See  Y<  1. 1.  page  73.) — He  ought 


246  Th  e Internal  Maxillary  Artery. 

• 

dyloid  process  of  the  lower  jaw,  and  extends  to  the 
bottom  of  the  zygomatic  fossa  : varying  its  direction 
in  its  course.  It  is  rather  larger  than  the  temporal. 

a.  It  first  sends  off  one  or  two  small  branches  to 
the  ear,  and  a twig  which  penetrates  into  the  cavity 
of  the  tympanum  by  the  glenoid  fissure. 

b.  It  also  sends  off  a small  artery  called  the  Les- 
ser Meningeal,  which  passes  upwards,  and  after 
giving  branches  to  the  external  pterygoid  and  the 
muscles  of  the  palate,  passes  through  the  foramen 
ovale,  and  is  spent  upon  the  dura  mater  about  the 
sella  turcica. 

c.  It  then  sends  off  one  of  its  largest  branches,  the 
Great  or  Middle  Artery  of  the  Dura  Mater , which 
passes  in  a straight  direction  to  the  foramen  spinale, 
by  which  it  enters  into  the  cavity  of  the  cranium. 

This  artery  ramifies  largely  on  the  dura  mater, 
and  makes  those  aboreseent  impressions  which  are 
so  visible  in  the  parietal  bone.  It  generally  divides 
into  two  great  branches : the  anterior,  which  is  the 
largest,  passes  over  the  anterior  and  inferior  angle  of 
the  parietal  bone:  the  posterior  branch  soon  divides 
into  many  ramifications,  which  are  extended  lateral- 
ly and  posteriorly. 

It  furnishes  the  twig  which  passes  to  the  ear  by 
the  hiatus  of  Fallopius,  and  anastomoses  with  the 
small  branches  of  the  stylo  mastoid  artery. 

It  also  supplies  some  other  small  vessels  which 
pass  to  the  cavity  of  the  tympanum  by  small  forami- 
na near  the  junction  of  the  squamous  and  petrous 
portions  of  the  temporal  bone. 

d.  The  next  branch  sent  off  by  the  internal  max- 
illary leaves  it  about  an  inch  from  its  origin,  and  is 

to  be  well  acquainted  with  this  subject,  if  he  should  undertake  the  man- 
agement of  necrosis  of  the  jaw  bones  ; or  of  those  fungous  tumours, 
which  sometimes  originate  in  the  antrum  iraxillare its  well  as  of  several 
other  complaints. 


The  Internal  Maxillary  Artery,  247 

called  the  Inferior  Maxillary . It  passes  between 
the  internal  pterygoid  muscle  and  the  bone,  and  after 
giving  small  branches  to  the  contiguous  miiscles,  en- 
ters the  canal  in  the  lower  jaw,  in  company  with  the 
nerve.  This  canal  has  a very  free  communication 
with  the  cellular  structure  of  the  jaw,  and  the  artery 
in  its  progress  along  it  sends  branches  to  the  respective 
teeth  and  the  bone.  At  the  anterior  maxillary  fora- 
men, this  artery  sends  off  a considerable  branch,  which 
passes  out  and  anastomoses  with  the  vessels  on  the 
chin,  while  another  branch  passes  forward  and  sup- 
plies the  canine  and  incisor  teeth  and  the  bone  con- 
tiguous to  them. 

Sometimes  the  inferior  maxillary  artery  divides 
into  two  branches  before  it  has  arrived  at  this  fora- 
men. In  this  ease,  one  of  thp  arteries  passes  out  of 
the  foramen,  while  the  other  continues  to  the  sym- 
phisis. 

e.  Two  branches  pass  off  to  the  temporal  muscle, 
which  originate  at  a small  distance  from  each  other  : 
one  of  them  passes  upwards  on  the  tendon  of  the 
temporal  muscle ; the  other  arises  near  the  tuberosity 
of  the  upper  maxillary  bone:  they  are  called  the  ex- 
terior deep , and  the  interior  deep  temporal  artery . 
They  are  both  spent  upon  the  temporal  muscle;  . but 
the  interior  branch  sends  a small  twig  into  the  orbit 
of  the  eye. 

F.  There  are  some  small  branches  which  pass  to 
the  Pterygoid  Muscles  and  to  the  Masseter , which 
arise  either  from  the  internal  maxillary  artery,  or  from 
the  anterior  deep  temporal.  They  are  generally  small, 
and  often  irregular, 

g..  An  artery,  particularly  appropriated  to  the 
cheek,  perforates  the  buccinator  muscle  from  within 
outwards,  and  generally  terminates  on  the  buccinator, 
the  zygomatieus  major  and  the  muscles  of  the  lips. 
This  Artery  of  the  Cheek  is  very  irregular  in  its 


248  The  Internal  Maxillary  Artery. 

origin,  sometimes  arising  from  the  internal  maxillary, 
sometimes  from  the  deep  temporal,  and  sometimes 
from  the  suborbitary,  or  from  the  alveolar  artery,  to 
be  immediately  described. 

h.  The  Alveolar  Artery,  or  the  Artery  of  the 
Upper  Jaiv,  arises  generally  from  the  internal  maxil- 
lary, but  sometimes  from  one  of  its  branches.  It  winds 
round  the  tuberosity  of  the  upper  jaw,  and  sends 
branches  to  the  buccinator  muscle,  to  the  bone  and 
the  gums,  to  the  antrum  highraorianum,  and  some  of 
the  molar  teeth:  and  also  to  the  teeth  generally,  by 
means  of  a canal  which  is  analogous  to  that  of  the 
lower  jaw. 

i.  The  Infra  orbitar  Artery  arises  from  the  inter- 
nal maxillary  in  the  zygomatic  fossa,  and  soon  enters 
the  infra  orbitary  canal,  through  which  it  passes  to 
the  face,  and  emerges  below  the  orbit  of  the  eye, 
supplying  the  muscles  in  the  vicinity,  and  anasto- 
mosing with  the  small  ramifications  of  the  two  last 
described  arteries,  and  also  of  the  facial  artery  and 
the  ophthalmic. 

This  artery  in  its  course  sends  off  small  twigs  to 
the  periosteum,  the  adipose  membrane,  and  the  mus- 
cles in  the  inferior  part  of  the  orbit,  and  also  to  the 
great  maxillary  sinus  or  antrum  highmorianum,  and 
to  the  canine  and  incisor  teeth. 

j.  The  Palato  Maxillary , or  Superior  Palatine 
Artery,  arises  also  in  the  zygomatic  fossa,  and,  de- 
scending behind  the  upper  maxillary  bone,  enters  the 
posterior  palatine  canal.  It  generally  forms  two 
branches,  the  largest  of  which  advances  forward, 
supplying  the  palate  and  gums,  and  finally  sends  a 
twig  through  the  foramen  incisivum  to  the  nose,  while 
the  posterior  branch,  which  is  much  smaller,  supplies 
the  velum  pendulum  palati. 

k.  The Ptery go  Palatine,  or  Superior  Pharnygeal, 
is  a small  vessel ; which  sometimes  arises  from  the 


249 


Temporal  Artery, 

artery  next  to  be  mentioned.  It  is  spent  upon  the 
upper  part  of  the  pharynx,  and  a branch  passes 
through  the  pterygo  palatine  foramen,  which  is  spent 
upon  the  arch  of  the  palate  and  the  contiguous  parts. 

L.  The  internal  maxillary  at  length  termi- 
nates in  the  Spheno- Palatine,  or  Large  Nasal  Ar- 
tery, which  passes  through  the  spheno-palatine  fora- 
men to  the  back  part  of  the  nose.  This  artery 
sometimes  separates  into  two  branches  before  it  en- 
ters the  foramen;  sometimes  it  enters  singly,  and 
divides  into  two  branches  soon  after;  one  of  them  is 
spread  upon  the  septum,  and  the  other  upon  the  ex- 
ternal side  of  the  nose ; each  of  these  branches  rami- 
fies very  minutely  upon  the  Schneiderian  membrane 
and  its  processes  in  the  different  sinuses,  and  also  in' 
the  ethmoidal  cells. 

8.  The  TEMPORAL  ARTERY 

Is  considered  as  the  continuation  of  the  external  ca- 
rotid, because  it  preserves  the  direction  of  the  main 
trunk,  although  the  internal  maxillary  is  larger. 

After  parting  with  the  internal  maxillary  it  pro- 
jects outwards ; and  passing  between  the  Meatus 
Auditorius  Externus  and  the  condyle  of  the  lower 
jaw,  continues  upwards,  behind  the  root  of  the  zygo- 
matic process  of  the  temporal  bone,  to  the  aponeuro- 
sis of  the  temporal  muscle : on  the  outside  of  which, 
immediately  under  the  integuments,  it  divides  into 
two  large  branches  denominated  anterior  and  poste- 
rior. 

Before  this  division  the  temporal  artery  sends  off 
several  branches  of  very  different  sizes. 

One,  which  is  considerable'in  size,  and  called  the 
Transverse  Facial  Branch,  advances  forwards  across 
the  neck  of  the  condyle  of  the  lower  jaw,  and  giving 
small  branches  to  the  masseter,  runs  parallel  to  the 
parotid  duct,,  and  below  it.  This  branch  is  spent 
Vol,  it.  • -32 


250  Temporal  Artery.-— Internal  Carotid . 

upon  the  muscles  of  the  face,  and  anastomoses  With 
the  other  vessels  of  that  part. 

The  temporal  gives  off  small  branches  to  the  pa- 
rotid gland  and  to  the  articulation  of  the  jaw.  From 
the  last  mentioned  branch  small  twigs  pass  to  the  ear, 
one  of  which  enters  the  cavity  of  the  tympanum  by 
tbe  glenoid  fissure. 

■While  this  artery  is  on  a line  with  the  zygoma,  it 
sends  off  a branch  called  the  middle  temporal  artery , 
which  penetrates  the  aponeurosis  of  the  temporal 
muscle,  and  ramifies  under  it  upon  the  muscle  in  an 
anterior  direction. 

The  two  great  branches  of  the  temporal  artery  are 
distributed  in  the  following  manner.  The  Anterior 
passes  up  in  a serpentine  direction  on  the  anterior 
part  of  the  temple,  and  supplies  the  front  side  of  the 
head,  and  the  upper  part  of  the  forehead. 

The  Posterior  extends  upwards  and  backwards, 
and  supplies  the  scalp  on  the  lateral  and  middle  part 
of  the  cranium,  and  also  the  bone. 

Ramifications  from  each  of  these  branches  anasto- 
mose on  the  upper  part  of  the  cranium  with  those  of 
its  fellow  of  the  opposite  side.  The  anterior  branch 
also  anastomoses  on  the  forehead  with  the  facial  and 
ophthalmic  artery;  and  the  posterior  branch  with  the 
occipital  artery  on  the  back  part  of  the  head. 

THE  INTERNAL  CAROTID  ARTERY 

Is  sometimes  called  the  Artery  of  the  Brain , as  it  is 
almost  entirely  appropriated  to  that  viseus. 

From  its  origin  to  the  commencement  of  its  rami- 
cations  the  course  of  this  blood  vessel  is  peculiarly 
tortuous.  In  consequence  of  which  the  force  of  the 
blood  in  it  is  greatly  diminished  before  it  arrives  at 
the  brain. 

An  instance  of  this  curvature  occurs  immediately 


Cnrmtnres  cf  the  Internal  Carotid . 251 

after  its  separation  from  the  external  carotid,  when  it 
protrudes  outwards  so  much  as  to  be  exterior  to  that 
vessel ; after  this  it  ascends  to  the  carotid  canal,  and. 
in  its  course  is  in  contact,  or  very  near  the  par  va- 
gum  and  intercostal  nerves. 

The  carotid  canal  in  the  os  petrosum  is  by  no 
means  straight;  it  forms  a semicircular  curve,  for- 
wards and  inwards;  and  its  upper  portion,  which  is 
nearly  horizontal,  opens  obliquely  against  the  body 
- of  the  sphenoidal  bone,  at  a small  distance  from  it. 
Therefore,  after  the  artery  lias  passed  through  the 
canal,  it  must  turn  upwards  to  get  fairly  into  the 
cavity  of  the  cranium ; and  of  course,  its  direction 
while  in  the  canal,  forms  almost  a right  angle  with 
its  direction  before  it  enters,  and  after  it  emerges 
from  it. 

In  consequence  of  this  curvature,  much  of  the  mo- 
mentum of  the  blood  must  be  impressed  upon  the 
cranium. 

After  the  artery  has  arrived  at  the  end  of  the  caro= 
tid  canal,  and  has  turned  upwards  to  get  within  the 
cavity  of  the  cranium,  it  bends  forwards,  and  passes 
nearly  in  a horizontal  direction,  through  the  caver- 
nous sinus  on  the  side  of  the  sella  turcica,  to  the  an- 
terior clinoid  process ; here  it  again  forms  a conside- 
rable curve,  which  is  directly  upwards,  and  then  it 
perforates  the  dura  mater. 

These  curvatures  must  also  deprive  the  blood  of 
the  carotid  of  a portion  of  the  momentum  which  it 
has  retained  after  leaving  the  bone. 

The  object  of  these  various  flexures  of  the  internal 
carotid  appears  to  be  analogous  to  that  of  the  Rete 
Mirabile  in  certain  quadrupeds,  which  is  formed  by 
the  division  of  this  artery  into  many  small  branches, 
that  reunite  again,  without  producing  any  other  ef- 
fect than  the  diminution  of  the  momentum  of  the 
blood . 


252 


Ophthalmic  Artery. 

During  its  course  from  the  place  of  bifurcation  to 
its  entrance  into  the  carotid  canal,  the  internal  carotid 
artery  very  rarely  sends  off  any  branches.  In  the 
canal  it  gives  off  a small  twig  which  enters  the  cavity 
of  the  tympanum ; and  sometimes  a second  which 
unites  with  the  Pterygoid  branch  of  the  internal 
maxillary. 

As  it  goes  by  the  sella  turcica,  it  passes  through 
the  cavernous  sinuses,  and  gives  off  two  branches 
which  are  called  the  Postet'ior  and  Anterior  Arteries 
of  the  Cavernous  Sinus  or  Receptacle. 

The  posterior  branch  goes  to  that  part  of  the  dura 
mater  which  is  connected  with  the  posterior  clinoid 
process,  and  the  cuneiform  process  of  the  occipital 
bone.  It  likewise  gives  branches  to  several  of  the 
nerves  which  are  contiguous,  and  to  the  pituitary 
gland. 

The  anterior  artery  also  gives  branches  to  the  con- 
tiguous nerves,  to  the  dura  mater,  and  the  pituitary 
gland. 

When  the  internal  carotid  turns  upwards  at  the 
anterior  clinoid  process,  it  sends  off  the 

OPHTHALMIC  ARTERY 

Which  passes  under  the  optic  nerve  through  the  fo- 
ramen opticum  into  the  orbit  of  the  eye,  and  is  about 
a line  and  a half  in  diameter. 

Although  this  artery  enters  the  orbit  under  the  op- 
tic nerve,  it  soon  takes  a position  on  the  outside  of  it, 
but  afterwards  gradually  proceeds  to  the  inner  side 
of  the  orbit,  crossing  over  this  nerve  in  an  oblique  di- 
rection, and  finally  passes  out  of  the  orbit  near  the  in- 
ternal angle.  In  this  spiral  course  it  sends  off  nu- 
merous branches,  viz. 

a.  To  those  parts  which  are  auxiliary  to  the  eye. 

b.  To  the  bail  of  the  eye. 


Branches  of  the  Ophthalmic  Artery.  253 

c.  To  the  cavity  of  the  nose,  through  small  fora- 
mina in  the  ethmoid  bone,  and 

d.  To  the  forehead  and  external  side  of  the  nose. 

These  branches  generally  go  off  in  the  following 

order. 

1.  The  Lachrymal  artery  arises  soon  after  the 
ophthalmic  arrives  within  the  orbit,  and  passes 
above  the  abductor  muscle  to  the  lachrymal  gland, 
where  it  terminates,  sending  off  many  small  branches 
in  its  course. 

2.  The  Central  artery  of  the  retina  also  leaves 
the  ophthalmic  soon  after  its  arrival  in  the  orbit:  it 
is  a small  vessel  which  penetrates  into  the  centre  of 
the  optic  nerve,  and  passing  with  it  into  the  eye  is 
spread  upon  the  internal  surface  of  the  retina.  Here 
it  appears  to  terminate  in  the  adult ; but  in  the  foetus 
it  is  continued  through  the  vitreous  humour  to  the 
capsule  of  the  crystalline  lens. 

3.  While  the  ophthalmic  is  passing  over  the  optic 
nerve  the  branches  which  enter  the  ball  of  the  eye 
leave  it.  Their  number  varies,  but  they  form  three 
classes,  viz.  The  Long  Ciliary , the  Short  Ciliary. 
and  the  Anterior  Ciliary  arteries.  (See  description 
of  the  eye,  vol.  i.  p.  352,)  the  supra  orbitary  and 
muscular  branches  leave  it  also  near  the  same  places. 

4.  The  Supra  Orbitary  Branch  often  gives  off 
several  muscular  twigs : but  it  passes  out  of  the  orbit 
through  the  supra  orbitar  foramen,  and  generally 
divides  into  two  branches,  one  of  which  is  spent 
upon  the  periosteum,  and  the  other  upon  the  skin 
and  muscles  of  the  forehead. 

5.  There  are  sometimes  two  muscular  branches,  a 
Superior  and  an  Inferior.  The  superior  branch  is 
often  deficient : when  it  exists  it  supplies  the  levator 
palpebrae,  the  levator  oculi,  obliquus  superior,  &c.  ; 
but  these  parts  are  often  supplied  by  the  branches 
above  mentioned.  The  supra  orbitar  so  frequently 


&o4  Branches  of  the  Ophthalmic  Artery* 

gives  off  branches  to  the  muscles  that  it  has  been 
called  the  Superior  Muscular  Branch.  The  inferior 
muscular  branch  is  more  constant.  It  commonly 
supplies  the  rectus  inferior,  the  adductor,  and  the 
inferior  oblique  muscles,  and  also  the  lachrymal  sac, 
and  the  lower  eyelid,  &c. 

When  the  artery  is  on  the  inside  of  the  nerve  it 
sends  off  the  two  branches  to  the  cavity  of  the  nose, 
viz,  The  Ethmoidal  Arteries  ; and  also,  branches  to 
the  eyelids. 

6.  The  Posterior  Ethmoidal  branch  is  first.  It 
passes  between  the  levator  and  abductor  muscles, 
and  above  the  obliquus  superior ; and  penetrates  the 
cavity  of  the  cranium  by  the  posterior  orbitary  fora- 
men : after  giving  some  twigs  to  the  dura  mater,  it 
passes  to  the  posterior  cells  of  the  ethmoid  by  the 
foramina  of  the  cribriform  plate  of  that  bone,  and 
sends  a small  branch  to  the  Schneiderian  membrane 
on  the  back  part  of  the  septum  of  the  nose. 

7.  The  Anterior  Ethmoidal  artery  arises  from  the 
ophthalmic  nearly  opposite  to  the  anterior  orbitary 
foramen,  through  which  it  passes:  and  after  enter- 
ing the  cranium  is  distributed  like  the  other  through 
some  of  a foramina  of  the  cribriform  plate  to  the 
anterior  cells  of  the  ethmoid  bone,  and  to  the  ante- 
rior part  of  the  Schneiderian  membrane  on  the  sep- 
tum of  the  nose,  to  which  it  sends  a considerable 
branch. 

In  its  course  it  sends  twigs  to  the  frontal  sinuses, 
and  to  the  dura  mater  and  its  falciform  process. 

8.  The  arteries  of  the  Palpebrse  are  called  Supe- 
rior and  Inferior ; they  leave  the  ophthalmic  near 
the  loop  or  pully  of  the  superior  oblique  muscle. 
The  inferior  comes  off  first ; it  sends  branches  to  the 
ligaments  of  the  tarsus,  the  caruncula  lachrymalis, 
and  the  parts  connected  with  the  cartilage  of  the  un- 
der eyelid,  and  unites  with  the  lachrymal  artery  near 


Brandies  of  the  Ophthalmic  Artery.  Carotid.  2 53 

the  external  canthus,  forming  ail  arch  called  the  In* 
ferior  Tarsal  Arch. 

9.  The  Superior  Artery  supplies  the  superior  part 
of  the  orbicularis  muscles,  the  ligament  and  carun- 
cula  also  : and  it  likewise  unites  with  a twig  of  the 
lachrymal,  and  forms  the  superior  tarsal  arch. 

Soon  after  sending  off  the  palpebral  branches,  the 
Ophthalmic  Artery  arrives  at  the  internal  canthus, 
and  then  finally  divides  into  two  branches,  the  nasal 
aiid  the  frontal. 

10.  The  Arasal  Branch  passes  above  the  superior 
part  of  the  lachrymal  sac  and  the  ligament  of  the 
eye-lid  to  the  nose  ; after  sending  a twig  to  the  fron- 
tal  muscle  and  the  lachrymal  sac,  it  passes  down  the 
side  of  the  nose  and  anastomoses  with  the  facial  ar- 
tery. 

11.  The  Frontal  Artery  is  not  so  large  as  the  na- 
sal ; it  generally  divides  into  three  parts.  . A super- 
ciliary branch  which  is  principally  spent  upon  the 
eyebrows ; a superficial  branch  which  is  spent  upon 
the  forehead ; and  a branch  which  is  distributed  to 
the  pericranium. 

The  mTEENAL  carotid,  soon  after  parting  with 
the  ophthalmic,  sends  off,  in  a posterior  direction,  a 
branch  to  join  one  from  the  vetebral  artery.  From 
its  distination  this  vessel  is  called  the  arteria  com - 
municans , 

After  this  it  sends  off  another  branch,  which  is  so 
large  that  it  may  be  considered  as  a continuation  of 
the  main  trunk  : this  is  called  the  middle  cadery  of 
the  brain,  or  the  Arteria  Sylviana.  It  runs  outwards 
nearly  in  the  direction  of  the  fossa  Sylvii,  which  se- 
parates the  anterior  from  the  middle  lobes  of  the  ce- 
rebrum. In  its  course  it  divides  and  subdivides  into 
numerous  branches  which  are  spread  upon  the  Pici 
Mater , and  finally  enter  the  surface  of  the  brain,  in  a 
very  minute  state. 


256  Right  and  Left  Subclavian  Arteries , 

The  internal  carotid  then  terminates  in  a branch 
which  is  smaller  than  the  last  mentioned,  and  from 
its  situation  is  called  the  Anterior  Artery  of  the 
Brain , or  Arteria  Callosa,  This  vessel  first  inclines 
towards  its  fellow  on  the  opposite  side,  and  after  ap- 
proaching within  half  an  inch  of  it,  forms  another 
curve,  and  runs  forward  to  the  anterior  part  of  the 
brain,  dividing  itself  gradually  into  branches  which 
pass  in  several  directions. 

When  these  anterior  arteries  are  nearest  to  each 
other,  a small  transverse  branch,  which  passes  at 
right  angles,  connects  them  together.  This  branch 
completes  the  anterior  part  of  the  Circle  of  Willis. 

It  crosses  immediately  before  the  sella  turcica  and 
pituitary  gland,  and  sends  off  branches.  Which  pass 
to  the  third  ventricle,  to  the  fornix  and  septum  luei- 
dum,  and  also  to  the  pia  mater. 

The  Anterior  Arteries  of  the  brain  also  send  off 
branches  to  the  optic  and  olfactory  nerves ; to  the 
opposite  surfaces  of  the  two  hemispheres  on  each 
side  of  the  falx  ; to  their  inferior  surfaces,  and  to  the 
corpus  callosum. 

They  have  likewise  some  branches  which  anasto- 
mose with  those  of  the  middle  artery  of  the  brain, 
and  of  the  vertebral  artery. 

The  SUBCLAV’IAN  Arteries. 

The  right  subclavian  may  be  considered  as  the 
continuation  of  the  arteria  innominata.  This  last 
mentioned  artery,  after  leaving  the  aorta,  forms  a 
curve  or  arch,  which  extends  obliquely  backwards 
and  outwards,  over  the  first  rib  to  the  axilla,  crossing 
the  trachea  in  its  course.  At  the  distance  of  an  inch 
and  a quarter,  or  an  inch  and  a half  from  its  origin, 
it  sends  of  the  right  carotid,  and  then,  assuming  the 
name  of  Right  Subclavian , continues  in  the  above 
stated  direction-  ' 


257 


The  Left  Subclavian  Jittery. 

The  chord  of  the  carve  of  this  artery,  and  the 
chord  of  the  curve  of  the  aorta,  are  not  in  the  same 
direction,  but  form  an  angle  with  each  other. 

The  position  of  the  left  subclavian  is  somewhat 
different  from  that  of  the  right.  Its  origin  is  posterior, 
and,  therefore,  the  direction  of  the  chord  of  its  curve 
is  more  immediately  lateral.  The  curve  or  arch  is 
also  smaller.  The  situation  of  the  two  subelavians 
as  relative  to  the  contiguous  parts,  is,  therefore, 
somewhat  different ; but  each  of  them  proceeds  be- 
tween the  anterior  and  the  middle  scaleni  muscles, 
and  when  they  have  arrived  at  these  muscles,  their 
respective  positions  are  very  similar. 

The  anterior  and  middle  scaleni  muscles  arise  from 
the  transverse  processes  of  several  of  the  cervical 
vertebrae,  and  are  inserted  into  the  first  rib,  one  be- 
fore the  other,  so  as  to  leave  a considerable  space  be- 
tween them.  The  subclavian  arteries  § pass  through 
this  3pace,  and  before  they  arrive  at  it,  but  when  they 
are  very  near  the  above  mentioned  muscles,  they 
send  off  several  very  important  branches  in  various 
directions,  viz.  to  the  cavity  of  the  cranium,  to  the 
parietes  of  the  thorax,  to  the  thyroid  gland,  and  to 
the  lower  part  of  the  neck. 

They  proceed  near  to  the  scaleni  muscles  before 
they  send  off  any  branches ; and  it  is  to  be  observed, 
that  the  subclavian  veins  which  correspond  with  these 
arteries,  are  anterior  to  them,  for  they  pass  before 
the  scaleni  muscles,  and  not  between  them. 

The  internal  mammary  Jlrtery 

Goes  downwards,  from  the  lower  and  anterior  part 
of  the  subclavian,  along  the  inner  side  of  the  anterior 
scalenus  muscle.  It  proceeds,  exterior  to  the  pleura, 
across  the  cartilages  of  the  true  ribs,  and  and  near  their 
middle  ; and,  continuing  between  the  cartilages  and 
the  diaphragm,  exterior  to  the  peritoneum,  term!* 
tTo h.  Ho  3fS 


258  Course  and  Distribution  of  the  Inferior 

nates  on  the  rectus  .abdominis  muscle,  in  branches 
which  anastomose  with  those  of  the  epigastric  artery. 
In  this  course  it  gives  branches  to  almost  all  the 
parts  to  which  it  is  contiguous,  viz.  to  the  muscles 
and  glands  at  the  lower  part  of  the  neck ; to  the 
thymus  gland  ; to  the  parts  in  the  intercostal  spaces; 
to  the  sternum ; to  the  mediastinum  and  pericar- 
dium ; to  the  diaphragm  and  to  the  muscles  of  the 
abdomen. 

From  some  of  its  ramifications  upon  the  parts  be- 
tween the  ribs,  small  branches  go  off  to  the  mamma, 
and  thereby  give  a name  to  the  artery.  There  is  also 
a small  vessel  which  is  sent  off  by  the  mammary  ar- 
tery, or  by  one  of  its  upper  branches,  which  accom- 
panies the  phrenic  nerve  to  the  diaphragm. 

The  inferior  thyroid  Artery 

Arises  from  the  upper  side  of  the  subclavian  nearly 
opposite  to  tKe  origin  of  the  internal  mammary.  It 
passes  upwards  and  inwards,  between  the  carotid 
artery  and  the  spine,  to  the  thyroid  gland  : then  it 
anastomoses  with  the  branches  of  the  superior  thyroid 
on  the  same  side,  and  with  those  of  its  fellow  on  the 
opposite  side. 

This  vessel  sometimes  sends  off  large  branches  to 
the  muscles  at  the  lower  part  of  the  neck. 

The  vertebral  Artery 

Arises  from  the  upper  and  posterior  part  of  the  sub- 
clavian. It  goes  upwards  and  backwards  between 
the  muscles  which  lie  on  the  front  of  the  spine,  and 
passing  under  the  transverse  process  of  the  sixth  or 
seventh  cervical  vertebra,  enters  into  the  canal  form- 
ed in  the  transverse  processes  of  the  vertebrae.  In 
this  course,  as  it  proceeds  from  the  «third  to  the  se- 
cond cervical  vertebra,  it  inclines  outwards  laterally  , 
and,  in  its  passage  from  the  traosvere  process  of 


Thyroid  and  the  Vertebral  Arteries,  259 

the  second  to  that  of  the  first  vertebra,  it  forms  a 
considerable  curve,  the  convexity  of  which  has  a 
lateral  and  external  aspect.  After  passing  the  trans- 
verse process  of  the  Atlas , it  is  turned  suddenly 
backwards,  in  a groove,  and  finally  passes  through 
the  great  occipital  foramen  into  the  cavity  of  the  cra- 
nium. It  then  proceeds  upon  the  cuneiform  process, 
of  the  occipital  bone,  under  the  Medulla  Oblongata , 
and  joins  its  fellow  so  as  to  form  an  acute  angle  with 
it  near  the  union  of  the  medulla  oblongata  with  the 
pons  Varojii.  From  each  of  the  vertebral  arteries, 
before  their  union,  there  generally  goes  off  a small 
branch  called  the  Posterior  Meningeal , which  is 
spent  upon  the  posterior  part  of  the  dura  mater. 

The  trunk  formed  by  the  union  of  the  vertebral 
arteries  is  called 

The  BASILAR  Artery . 

It  extends  forward  near  to  the  anterior  part  of  the 
pons  Varolii,  where  it  bifurcates ; but  previously 
sends  off  several  branches  on  each  side.  The  first 
pair  go  off  in  a lateral  direction,  soon  after  its  com- 
mencement, near  the  back  part  of  the  pons  Varolii, 
and  are  spent  upon  the  medulla  oblongata,  the  pons 
Varolii,  and  the  other  contiguous  parts,  and  also 
upon  the  fourth  ventricle  and  the  Plexus  Choroides 
of  that  cavity.  They  are  called  the  Posterior  or 
Inferior  Arteries  of  the  Cerebellum. 

Two  other  lateral  branches,  which  are  called  the 
Superior  Arteries  of  the  Cerebellum , go  off  from  the 
Basilar  artery,  near  its  anterior  extremity.  These 
are  principally  spent  upon  the  crura  of  the  cerebel- 
lum and  cerebrum ; upon  the  cerebellum  itself,  and 
the  contiguous  parts. 

Soon  after  sending  off  the  last  mentioned  arteries, 
the  Basilar  artery  divides  into  two  branches,  which 
also  take  a lateral  direction,  and  are  of  considerable 


260  Arteries  of  the  lower  part  of  the  JYech. 

size.  In  their  course  outward,  these  branches  are 
curved  with  their  convexity  forward.  About  ten  of 
twelve  lines  from  its  commencement,  each  of  them 
sends  off  a branch  called  the  Arteria  C omnium  cans?  - 
which  passes  directly  forward,  and  communicates 
with  the  internal  carotid,  thus  forming  the  arrange- 
ment which  is  called  the  Circle  of  Willis .*  After 
sending  off  these  arteries,  they  continue  their  lateral 
direction,  and  are  distributed  principally  to  the  pos- 
terior parts  of  the  cerebrum.  These  terminating 
branches  of  the  Basilar  Artery , are  called  the  Pos- 
terior Arteries  of  the  Cerebrum . 

The  superior  intercostal  Artery 

Arises  from  the  upper  part  of  the  Subclavian , after 
the  Vertebral  and  Thyroid  arteries,  and  very  near 
them.  It  descends  by  the  side  of  the  spine  across 
the  first  and  second  ribs,  near  their  heads,  and  exte- 
rior to  the  great  intercostal  nerve.  It  generally  forms 
two  branches,  which  are  appropriated  to  the  mus- 
cles, &c.  in  the  first  and  second  intercostal  spaces, 
and  sometimes  a small  branch  is  continued  to  the 
third  intercostal  space.  From  each  of  these  branches 
a small  vessel  proceeds  backwards,  and  is  spent  upon 
the  contiguous  muscles,  &c.  on  the  back  of  the  tho» 
rax.  The  Intercostal  Artery  also  sends  a branch 
upwards  to  the  deep-seated  parts  of  the  neck. 

In  addition  to  the  arteries  above  mentioned,  there 
are  several  others  of  considerable  size  which  origi- 
nate either  directly  or  indirectly  from  the  subcla- 

* The  arteria  communicans  is  also  considered  as  a branch  of  the  Inter- 
nal Carotid.  The  arrangement  here  alluded  to  is  very  remarkable.  As 
the  branches  which  pass  off  laterally  from  the  single  trunk  of  the  Basilar 
Jittery  unite  to  the  Internal  Carotids,  and  the  Internal  Carotids  are  united 
to  each  other,  there  is  an  uninterrupted  continuation  of  artery.  Which  en- 
closes a portioh  of  space  of  a determined  form ; but  this  form  resembles 
an  oblong  square  more  than  a circle.  By  this  connexion  blood  will  pas? 
from  any  one  of  the  four  arteries  of  t’ne  brein  <o  all  the  others. 


Branches  that  go  off  in  the  Axilla,  261 

Vi  an,  and  are  spent  upon  the  lower  portion  of  the 
neck,  and  the  contiguous  parts.  These  arteries  are 
very  different  in  different  subjects,  especially  as  to 
their  origin.  Two  of  them,  which  have  been  called 
the  Anterior  and  Posterior  Cervieals,  are  generally 
distributed  to  the  muscles  and  other  parts  which  lie 
on  the  lower  portion  of  the  neck  anteriorly  and  pos- 
teriorly. 

A third,  which  passes  transversely  on  the  lower 
part  of  the  neck,  is  called  the  Superior  Scapular. 

In  some  cases  the  two  Cervical  Arteries  arise  from 
the  subclavian,  after  the  mammary  and  the  thyroid, 
in  a common  trunk,  which  soon  divides.  Very  fre- 
quently they  go  off  from  the  Inferior  Thyroid. — 
Sometimes  one  of  them  goes  off  from  the  Inferior 
Thyroid , and  the  other  from  one  of  the  branches  of 
tho  Subclavian .* 

The  Superior  Scapular  most  commonly  arises  with 
some  other  artery,  and  very  often  from  the  Inferior 
Thyroid.  It  runs  transversely  outwards,  within  and 
above  the  clavicle,  and  passing  through  the  notch  in 
the  upper  costa  of  the  scapula,  divides  into  branches 
which  are  distributed  to  the  parts  on  the  dorsum  of 
that  bone. 

The  subclavian  artery,  in  Its  progress  from  the 
aorta  to  the  axilla,  forms  an  arch  or  curve,  over  the 
first  rib,  as  has  been  already  observed.  The  ante- 
rior scalenus  muscle  is  before  it,  and  the  great  nerves 
of  the  upper  extremity  are  above  it.  After  passing 

* Haller  paid  great  attention  to  the  arterial  system,  and  made  many  dis- 
sections, with  a view  to  engravings  of  it,  which  he  published  with  descrip- 
tions, in  folio  fasciculi. 

These  fasciculi  have  been  collected,  and,  with  some  other  engravings, 
form  a large  volume,  entitled  icones  anatomic.se,  which  is  truly  valuable. 

There  are  some  very  interesting  observations  on  tills  work  of  Haller’s, 
and  also  on  these  arteries,  in  a description  or  the  arteries,  by  Dr.  Bar- 
clay of  Edinburgh,  which  I have  read  with  advantage,  as  well  as  a work 
on  the  muscles  by  the  same  author. 


£62  Branches  that  go  off  in  the  Axilla. 

between  the  scaleni  it  descends  upon  the  first  and 
second  rib  into  the  axilla.  The  nerves  which  were 
above,  descend  with  it : at  first  they  are  necessarily 
exterior  to  it,  but  they  form  a plexus  which  the 
artery  enters  into,  so  as  to  be  partly  surrounded,  by 
them.  This  course  of  the  artery  is  obliquely  under 
the  clavicle,  and  behind  the  pectoral  muscle.  In  the 
axilla,  the  vessel  and  nerves  which  surround  it  are 
placed  between  the  tendons  of  the  pectoralis  and  the 
latissimus  dorsi  muscles.  Here  the  artery  takes  the 
name  of  axillary,  and  sends  off  several  important 
branches. 

The  principal  branches  that  go  off  from  the  axil- 
lary artery  are  distributed, 

1st.  Anteriorly,  to  the  pectoral  muscle,  and  the 
parts  on  the  anterior  surface  of  the  thorax. 

2d.  Posteriorly,  to  the  muscles  which  are  on  the 
scapula  and  contiguous  to  it ; and 

3d.  To  the  parts  which  are  near  the  upper  extre- 
mity of  the  os  humeri. 

Anterior  Branches . 

The  arteries  which  go  to  the  pectoral  muscle,  &e. 
are  very  various  in  different  subjects,  both  as  to  their 
number,  origin,  and  size. 

They  have  also  been  called  by  different  names,  as 
Thoracicse,  Mammarise  Externse , fyc. 

There  are  almost  always  three  of  them,  and  very 
often  more  5 one  of  them,  which  is  called  by  several 
authors  the  Acromialis,  proceeds  towards  the  end  of 
the  clavicle,  and  generally  passes  out  at  the  interval 
between  the  deltoid  and  the  pectoral  muscle,  sending 
various  branches  to  the  contiguous  parts ; the  largest 
of  its  branches  often  passing  in  the  direction  of  the 
interstice  between  those  muscles. 

Another  of  these  arteries,  which  is  called  Superior 


Branches  that  go  off  in  the  Axilla.  263 

Thoracic , is  generally  very  small : it  often  is  a branch 
of  the  above  mentioned  Acromialis. 

There  is  very  often  to  be  found  here  an  artery 
called  the  Inferior  Thoracic , or  the  External  Mam- 
mary, which  is  of  considerable  length,  although  its 
diameter  is  not  very  great.  This  artery  originates 
near  the  two  last  mentioned,  and  sometimes  from  the 
Acromialis.  It  often  extends  downwards  as  low  as 
the  sixth  rib,  and  send  branches  to  the  anterior  part 
of  the  thorax,  to  the  mamma,  and  the  other  contigu- 
ous parts.  Many  of  the  small  branches  of  this  ar- 
tery anastomose  very  freely  with  those  of  the  inter- 
nal mammary. 

There  are  always  small  arterial  branches  in  the 
axilla,  which  ramify  upon  the  glands  and  adipose 
matter  always  existing  there.  They  often  arise  by 
one  commom  trunk,  which  is  called  the  Axillary 
Thoracie . 

Posterior  Branch . 

One  large  artery  is  commonly  sent  to  the  muscles 
on  the  scapula,  which  is  called  the  Scapular , the 
Common  Scapular,  or  the  Internal  Scapular.  It 
commonly  passes  off  from  the  axillary  after  the  tho- 
racic arteries,  and  supplies  the  muscles  on  both  sur- 
faces of  the  scapula.  This  large  vessel  passes  down- 
wards a short  distance  in  the  direction  of  the  inferior 
costa  of  the  scapula,  and  soon  sends  off  a branch 
that  winds  round  to  the  dorsum  of  the  bone,  to  be 
distributed  to  the  infra  spinatus  and  the  contiguous 
muscles,  which  is  called  the  Dorsalis  Scapulse.  The 
main  trunk  then  inclines  to  the  subscapularis  muscle, 
and  generally  divides  into  two  branches,  which  are 
distributed  to  the  subscapularis,  teres  major,  latissi- 
mus  dorsi,  &c. 

Sometimes  the  Scapular  artery  divides  into  two 
branches  before  it  sends  off  the  dorsal.  In  this  case 


264  Humeral  Artery. 

the  last  mentioned  artery  goes  off  from  one  of  those 
branches. 

Branches  near  the  Os  Humeri . 

The  arteries  which  are  near  the  body  of  the  os 
humeri  at  its  upper  end,  are  generally  two  in  number, 
and  denominated  the  Anterior  and  Posterior  Circum* 
flex.  Sometimes  they  arise  separately,  and  some- 
times in  a common  trunk  from  the  axillary  artery. 
Frequently  one  of  them  arises  from  the  scapular. 

The  Anterior  Circumflex  passes  between  the 
united  heads  of  the  biceps  and  coraco-brachialis  mus- 
cles and  the  body  of  the  os  humeri,  at  a small  distance 
below  its  head.  It  sends  branches  to  the  capsular  li- 
gament, the  periosteum  of  the  os  humeri,  the  mem- 
branes of  the  groove  for  the  long  head  of  the  biceps, 
the  upper  portions  of  the  biceps  and  coraco-brachia« 
lis,  and  some  contiguous  muscles. 

The  Posterior  Circumflex  proceeds  between  the 
subscapularis  and  teres  major  muscles,  and  continues 
between  the  os  humeri  and  the  head  of  the  triceps 
and  the  deltoides.  It  is  distributed  to  the  muscles 
and  parts  about  the  joint,  especially  the  deltoides. 

These  arteries  surround  the  os  humeri,  and  the 
small  branches  anastomose  with  each  other.  The 
Posterior  Circumflex  is  much  larger  than  the  Ante- 
rior. 

The  great  artery  of  the  arm  proeeeds  from  the 
axilla  to  the  elbow;  and,  during  this  course,  is  gene- 
rally denominated 

The  HUMERAL  Artery 

Its  direction  is  influenced  by  the  position  of  the  os 
humeri.  When  the  arm  hangs  down,  with  the  palm 
of  the  hand  presenting  forward,  this  direction  is 

It  is  called  Brachial  Artery  by  several  Writers. 


Branches  of  the  Humeral  Artery.  265 

somewhat  spiral.  The  situation  of  the  artery  is  on 
the  inside  of  the  biceps  muscles,  and  between  that 
muscle,  and  the  triceps  extensor.  It  also  continues 
very  near  and  on  the  inside  of  the  tendon  of  the  bi- 
ceps, and  under  the  Aponeurosis  which  proceeds 
from  that  tendon.  In  consequence  of  the  spiral  or 
oblique  course  of  the  artery,  its  direction  would  be 
from  the  inside  of  the  tendon  of  the  biceps  to  the  ra- 
dial side  of  the  fore  arm,  but  soon  after  it  passes 
across  the  joint  of  the  elbow,  it  divides  into  two 
branches : one  which  preserves,  for  some  distance, 
the  direction  of  the  Main  Trunk,  is  called  the  Ra- 
dial artery : the  other,  which  inclines  obliquely  down- 
wards and  towards  the  ulna,  is  the  Common  Trunk 
of  the  Ulnar  and  Interosseal  arteries. 

During  this  course,  the  humeral  artery  sends  off 
several  branches  to  the  muscles  and  other  parts  on  the 
os  humeri.  The  largest  of  them  is  denominated  the 
Profunda  Humeri  or  Spiralis.  This  artery  very 
often  arises  as  high  as  the  insertion  of  the  latissimus 
dorsi,  and  passing  between  the  heads  of  the  triceps 
extensor  muscle,  proceeds  downwards  under  that 
muscle,  in  a spiral  direction,  towards  the  external 
or  radial  condyle.  It  sends  several  branches  to  the 
triceps  and  the  contiguous  muscles,  and  one  consider, 
able  branch,  which  is  generally  called  the  Profunda 
Minor , to  the  parts  contiguous  to  the  internal  con- 
dyle. The  ramification  of  these  branches  near  the 
condyle  frequently  anastomose  with  small  branches  of 
the  radial  and  ulnar  arteries.* 

A small  branch  frequently  arises  from  the  Hume- 
ral artery,  at  a short  distance  from  the  Profunda 
Humeri , which  sends  a ramification  to  the  medullary 

* The  Profunda  sometimes  originates  from  the  scapular,  or  one  of  the 
circumflex.  The  profunda  minor  sometimes  has  a distinct  and  separate 
origin,  lower  down  than  the  other. 

Vol.  n,  34 


266 


Radial  Artery. 

foramen  of  the  os  humeri.  This  vessel  is,  therefore, 
denominated  Arteria  JYutritia. 

There  are  very  often  several  anastomoses  between 
the  branches  of  the  humeral  artery,  which  originate 
above  the  elbow,  and  certain  branches  of  the  Radial 
and  Ulnar  arteries,  which  are  called  from  their  di- 
rection recurrents.  Among  these  arteries  there  is 
generally  one  of  considerable  size,  which  proceeds 
across  the  elbow  joint  near  the  internal  condyle.— 
Sometimes  this  is  the  ulnar  recurrent,  which  goes  up 
to  anastomose  with  the  branches  of  the  profunda ; 
but  more  frequently  it  is  a separate  branch  of  the 
Humeral  artery  which  goes  off  a little  above  the 
elbow,  and  passes  across  the  articulation,  near  the 
internal  condyle,  to  anastomose  with  tbe  branches  of 
the  ulnar  artery.  This  artery  is  denominated  the 
Anastomotica. 

There  are  often  other  branches  sent  off  by  the 
humeral  artery ; but  they  are  commonly  small,  and 
very  irregular. 

The  two  great  ramifications  of  the  humeral  ar- 
tery on  the  fore  arm  have  very  different  directions. 
The  Radial  artery  preserving  the  course  of  the  main 
trunk,  while  the  Common  Trunk  of  the  Ulnar  and 
Interosseal  projects  from  it  in  a direction  downwards 
and  towards  the  ulna,  passing  under  the  pronator 
teres,  &c. 

The  radial  Artery 

Passing  over  the  pronator  teres  muscle  proceeds  be- 
tween the  supinator  radii  longus  and  the  flexor  carpi 
radialis,  very  near  to  the  lower  end  of  the  radius, 
without  changing  its  direction  materially,  being  deep- 
seated  above  and  superficial  below ; it  then  alters  its 
course,  and,  passing  under  the  tendons  of  the  exten- 
sors of  the  thumb,  to  the  back  part  of  the  radius,  it 


Course  and  Ramifications  of  the  Radial  Artery . 267 

continues  between  the  metacarpal  bones  of  the  thumb 
and  of  the  index  finger,  when  it  divides  into  three 
branches. 

In  this  course  it  gives  off  but  few  branches.  The 
first  is  the  Radial  Recurrent,  which  passes  upwards 
and  towards  the  external  condyle,  and  frequently 
anastomoses  with  the  ramifications  of  the  profunda 
humeri. 

The  branches  which  it  sends  off  between  the  origin 
of  the  recurrent  and  the  lower  end  of  the  radius  arc 
generally  very  small,  and  distributed  to  the  parts  im- 
mediately contiguous  to  the  artery.— Before  it  turns 
under  the  tendons  of  the  extensors  of  the  thumb,  it 
sends  a branch  over  the  wrist  towards  the  root  of  the 
thumb,  from  which  proceeds  a branch  to  anastomose 
with  the  volar  branch  of  the  ulnar ; and  another,  not 
so  large,  which  is  frequently  continued  on  the  radial 
or  external  side  of  the  thumb,  very  near  to  its  extre- 
mity. While,  the  radial  artery  is  under  the  aforesaid 
tendons,  it  sends  off  small  branches  to  the  back  of 
the  wrist  and  back  of  the  hand,  and  often  to  the 
back  of  the  thumb.  Those  which  are  distributed  to 
the  wrist  and  back  of  the  hand,  generally  anastomose 
with  the  small  branches  of  the  ulnar  and  interosseal 
arteries. 

The  three  branches  into  which  the  radial  artery 
divides  between  the  metacarpal  bones  of  the  thumb 
and  index  are,  1st,  a branch  to  the  external  side  of 
the  index  ; 2dly,  a branch  to  the  thumb,  that  some- 
times divides  into  two  which  pass  up  on  the  anterior 
or  volar  surface,  and  sometimes  continues,  without 
much  diminution,  on  the  internal  side  of  the  thumb, 
near  to  the  end  of  the  last  phalanx ; and,  3dly,  a 
branch,  called  Palmaris  Profunda , which  dips  down 
into  the  palm  of  the  hand,  and,  proceeding  in  con- 
tact with  the  metacarpal  bones,  under  the  flexor 
tendons,  forms  an  arch  which  extends  across  the 


268  Origin  of  the  Ulnar  and  Interosseal  Arteries. 

hand,  and  often  terminates  by  anastomoses  with  an- 
other arch,  soon  to  be  described,  which  is  formed  by 
the  ulnar  artery. 

This  flexure,  which  is  denominated  Arcus  Pro- 
fundus, sends  off  branches  of  a very  small  size,  which 
are  distributed  to  the  bones,  ligaments,  muscles,  &c. 
contiguous  to  it. 

The  common  trunk  of  the  ulnar  and  interos- 
seal Arteries 

Passes  under  several  of  the  muscles  which  originate 
from  the  internal  condyle,  and  between  the  flexor 
sublimis  and  the  flexor  profundus.  Before  the  Ulnar 
Recurrent  goes  off  from  this  vessel,  the  interosseal 
artery  often  leaves  it.  This  recurrent  artery  passes 
upwards  between  the  muscles  of  the  internal  condyle, 
and  distributes  branches  among  them.  It  then  passes 
up  in  the  groove  behind  the  internal  condyle,  and 
anastomoses  with  the  branches  of  the-  Anastomotica 
or  Profunda  Humeri. 

The  ulnar  and  interosseal  arteries  separate  from 
each  other  at  the  distance  of  fifteen  or  twenty  lines 
from  the  origin  of  the  radial  artery,  very  near  the 
commencement  of  the  interosseal  ligament. 

The  interosseal  Artery 

In  a majority  of  cases,  arises  in  a single  branch  from 
the  common  trunk  of  the  ulnar  and  interosseal.  When 
it  does  so,  the  single  branch  soon  sends  off  the  Pos- 
terior Interosseal  artery,  which  perforates  the  inte- 
rosseous ligament,  and  passes  down  on  its  posterior 
surface,  while  the  main  branch  continues  on  the  an- 
terior surface  of  the  ligament,  and  is  denominated 
the  Anterior  Interosseal  Artery.  In  some  cases  the 
main  branch  proceeds  on  the  anterior  surface  as  low 
as  the  upper  edge  of  the  pronator  quadratus  muscle, 
before  it  sends  off  tlie  posterior  branch,  Sometimes 


269 


Course  of  the  Ulnar  Artery. 

the  anterior  and  posterior  interosseals  arise  separate- 
ly. In  this  ease  the  posterior  soon  perforates  the  li- 
gament. 

The  Anterior  Interosseal  passes  down  almost  in 
contact  with  the  ligament,  and  gives  branches  to  the 
contiguous  parts  in  its  course.  It  generally  perforates 
the  interosseous  ligament  near  the  wrist,  and  sends 
off  many  small  branches  to  the  back  of  the  wrist  and 
hand,  which  anastomose  with  the  small  branches  of 
the  radial  and  the  posterior  interosseal  arteries. 

The  Posterior  Interosseal  soon  gives  off  a recur- 
rent or  anastomosing  branch,  and  then  proceeds  down- 
wards towards  the  wrist,  sending  branches  in  its 
course  to  the  extensor  muscles  and  tendons. 

This  vessel  sometimes  divides  into  two  branches. 

The  ulnae  Artery. 

The  Ulnar  artery  proceeds  among  the  muscles  ob= 
liquely  downwards,  and  is  not  superficial  until  it  has 
arrived  within  three  or  four  inches  of  the  carpus : it 
then  continues  towards  the  hand,  sending  off  very 
small  branches  in  its  progress.  It  passes  over  the 
annular  ligament  at  the  wrist,  and  winds  round  the 
pisiform  bone : here  it  is  supported  by  a delicate  liga- 
ment, which  seems  to  lie  upon  it:  from  this  it  passes 
upon  the  palm  of  the  hand,  under  the  aponeurosis 
palmaris,  and  over  the  tendons  of  the  flexors  of  the 
fingers.  When  thus  situated,  it  forms,  in  perhaps  a 
majority  of  subjects,  an  arch  or  bow,  called  Arcus 
Sublimis,  which  extends  across  the  palm  of  the  hand, 
from  the  ulnar  towards  the  radial  edge,  and,  after 
sending  branches  to  the  fingers,  &c.  from  its  convex 
side,  terminates  near  the  root  of  the  thumb,  by  anas- 
tomosis with  that  important  branch  of  the  radial  ar- 
tery, which  passes  up  on  the  inside  of  the  thumb. 


270 


Digital  Jirt fries. 

The  Jlrcus  Sublimis  almost  always  sends  off  small 
branches  to  the  integuments,  &c.  on  the  palm  of  the 
hand.  It  often  sends  off,  near  the  root  of  the  meta- 
carpal bone  of  the  little  finger,  a branch  which  passes 
between  the  flexor  tendons  and  the  metacarpal  bones, 
and  anastomoses  with  the  jlrcus  Profundus.  It  then 
generally  sends  off  a branch  to  the  inner  or  ulnar 
side  of  the  little  finger ; and  afterwards  three 
branches  in  succession,  which  pass  from  its  convex 
side  towards  the  angles  formed  by  the  fingers.  These 
are  called 

The  Digital  Arteries. 

When  they  have  arrived  near  to  the  heads  of  the 
first  phalanges  of  the  fingers,  each  of  these  arteries 
divides  into  two  branches,  one  of  which  passes  along 
the  side  of  one  of  the  fingers  to  its  extremity,  and  the 
other  on  the  opposite  side  of  the  next  finger  : and  in 
this  way  they  pass  on  the  sides  of  all  the  fingers,  ex- 
cept the  inside  of  the  little  finger  and  the  outside  of 
the  index. 

These  branches  of  the  digital  arteries  are  called 
Digito  Radial  and  Digito  XJlnar  arteries,  according 
to  the  sides  of  the  fingers  on  which  they  are  placed. 
They  are  situated  on  the  angle,  if  it  may  be  so  term- 
ed, which  is  formed  by  the  anterior  and  lateral  sur- 
faces of  each  finger.  In  their  course  from  the  basis 
to  the  extremity  of  the  finger,  they  send  off  very 
small  transverse  branches,  which  anastomose  with 
each  other,  especially  near  the  other.  Some  trans- 
verse branches  are  observable  on  the  posterior  as 
well  as  the  anterior  surfaces.  Near  the  extremity 
of  each  finger,  beyond  the  insertion  of  the  flexor 
tendon,  the  extremities  of  these  arteries  ramify  mi- 
nutely. Some  of  these  small  branches  go  to  the 
skin,  and  others  anastomose  with  their  fellows  of 


Bronchial  Artery.  271 

the  opposite  side.  Some  also  go  to  the  back  of  the 
fingers.* 


section  nr. 

Of  the  Branches  which  go  off  between  the  arch  and 
the  great  bifurcation  of  the  AORTA. 

PART  I. 

In  the  Cavity  of  the  Thorax. 

THE  arorta  sends  branches  to  the  Lungs,  to  the 
oesophagus,  and  to  the  parietes  of  the  thorax. 

The  bronchial  Arteries 

Are  the  vessels  which  go  from  the  aorta  to  the  ram- 
ifications of  the  trachea,  and  the  substance  of  the 
lungs.  They  are  not  large,  and  are  very  irregular 
as  to  number  and  origin. 

In  a majority  of  cases  the  right  lung  is  supplied,  in 
part,  by  a branch  from  the  first  aortic  intercostal  of 
that  side  ; while  the  left  lung  receives  two  or  three 
branches  from  the  aorta  directly.  In  some  eases  a 
large  vessel  arises  from  the  aorta,  which  divides  into 
two  branches,  one  of  which  goes  to  each  lung. 

* The  distribution  of  the  radial  and  uinar  arteries  in  the  hand,  is  very 
different  in  different  subjects. 

Upon  examining  a large  number  of  injected  preparations  in  Philadelphia, 
it  was  found  that,  in  a very  small  majority  of  them,  the  ulnar  artery  form- 
ed  an  arcus  sublimis,  whose  branches  extended  as  far  as  the  ulnar  side  of 
the  index,  and  sometimes  beyond  it. 

That,  in  near  a third  of  the  preparations,  the  ulnar  artery  ramified  with- 
out forming  an  arcus,  and  supplied  only  two  of  the  digital  branches,  viz, 
the  first  two  on  the  ulnar  side.  In  such  cases  the  radial  artery  generally 
made  up  the  deficiency  of  the  ulnar,  but  in  a few  instances  the  interosseal 
wa6  extended  on  the  palm  of  the  hand,  and  supplied  the  radial  side  of  the 
middle  finger  and  the  corresponding  side  of  the  index. 

In  a few  instances  also  the  ulnar  artery  was  still  more  deficient,  and  the 
radial  was  proportionally  extended. 


272  (Esophageal  and  Intercostal  Arteries, 

The  Bronchial  arteries  frequently  send  small 
branches  to  the  posterior  mediastinum,  the  pericar- 
dium, &c. 

Injections  have  shown,  that  there  is  a direct  com- 
munication between  these  vessels  and  the  branches 
of  the  pulmonary  artery. 

The  (Esophageal  Arteries 

Are  very  small  vessels,  which  generally  arise  from 
the  aorta,  but  sometimes  are  branches  of  the  bron- 
chials  or  intercostals  that  are  spent  upon  the  oesopha- 
gus. They  occur  in  succession,  and  sometimes  are 
five  or  six  in  number.  They  also  send  twigs  to  the 
contiguous  parts,  and  the  lowermost  often  descend  to 
the  stomaeh. 

The  Inferior  Intercostals 

Are  the  arteries  which  proceed  directly  from  the 
aorta  to  the  parietes  of  the  thorax.  Their  name  is 
derived  from  their  position  between  the  ribs.  They 
are  ramified  on  the  intercostal  muscles  and  ribs,  and 
on  the  pleura  and  some  of  the  contiguous  parts.  They 
are  called  Inferior  or  Aorta  Intercostals,  to  distin- 
guish them  from  the  superior  intercostals,  which  are 
derived  from  the  subclavian  artery.  Their  number 
varies  from  ten  to  eight,  according  as  the  superior 
intercostals  are  more  or  less  numerous. 

They  originate  in  pairs  on  the  posterior  surface  of 
the  aorta.  The  uppermost  of  them  pass  obliquely 
upwards,  and  the  lowermost  nearly  in  a horizontal 
direction,  to  the  lower  edges  of  those  ribs  to  which 
they  are  appropriated.  They  meet  the  rib  near  its 
tubercle,  or  place  of  junction  with  the  transverse 
process  of  the  vertebra,  and  then  proceed  forward, 
between  the  internal  and  external  intercostal  mus- 
cles, in  a superficial  but  large  groove,  which  is  ge- 


Intercostal  Arteries. 


273 


tierally  to  be  found  on  the  interior  margin  of  the 
lower  surface  of  the  rib.*  There  is  necessarily  a 
difference  in  the  length  of  the  right  and  left  inter- 
costals,  owing  to  the  position  of  the  aorta,  which  is 
s’ather  on  the  left  of  the  spine.  In  consequence  of 
this  circumstance,  the  oesophagus  is  anterior  to,  and 
also  in  contact  with  those  of  the  right  side. 

They  generally  send  off  an  important  branch,  call- 
ed the  Dm'sal,  which  arises  near  their  origin,  and, 
passing  backwards,  sends  ramifications  to  the  mus- 
cles of  the  back.  From  this  dorsal  branch  also  pro- 
ceeds a ramification,  which  enters  the  spinal  cavity, 
and  is  spent  upon  its  membrane  and  upon  the  medulla 
spinalis. 

After  the  Intercostals,  in  their  progress  forward, 
have  passed  beyond  the  middle  of  the  ribs,  they  send 
off  a branch,  which  generally  proceeds  very  near  to 
the  upper  side  of  the  lower  rib.  The  main  trunk 
generally  leaves  the  lower  edge  of  the  rib  when  it 
has  arrived  within  one-third  of  the  length  of  the  bone 
from  its  anterior  extremity.  It  then  generally  di- 
vides into  several  branches,  some  of  which  are  spent 
upon  the  pleura,  and  others  on  the  intercostal  and 
the  contiguous  muscles. 

According  to  the  situation  of  the  different  inter- 
costals, some  of  their  ramifications  communicate  with 
those  of  the  internal  and  external  mammaries,  of  the 
phrenic,  the  lumbar,  or  the  epigastric  arteries. 

* See  Vol.  I.  page  95. 


35 


Vol.  n. 


274 


Cavity  of  the  Abdomen . 


PART  II. 

In  the  Cavity  of  the  Abdomen . 

The  aorta  passes  into  the  cavity  of  the  abdomen 
between  the  crura  of  the  diaphragm,  as  has  been  al- 
ready mentioned.  In  its  course  from  the  crura  to  its 
great  bifurcation,  it  sends  off  one  pair  of  small  arte- 
ries,  called  Phrenie , to  the  diaphragm.  Three  sin- 
gle arteries,  the  cceliac,  the  superior,  and  the  in- 
ferior mesenteric,  to  the  viscera  of  the  abdomen. 
A pair  of  large  arteries,  the  emulgents,  to  the  kid- 
neys, with  several  that  are  very  small  to  their  ap- 
pendages ; as  the  Spennatices,  Capsular , the  Ure- 
teric, and  the  Adipose . In  addition  to  these,  there 
is  one  pair  of  small  arteries  that  go  to  the  testicles, 
or  to  the  ovaria  and  the  uterus,  and  four  or  live  pair, 
called  Lumbar  Arteries,  that  go  off  laterally,  like 
the  intercostals,  to  the  parietes  of  the  abdomen,  and 
to  the  muscles,  &c.  on  the  back,  which  are  contiguous 
to  them. 

The  phrenic  Arteries 

Are  ramified  on  the  concave  surface  of  the  dia- 
phragm, and  are  almost  always  two  in  number  ; they 
are  denominated  right  and  left  from  their  position. 
They  commonly  originate  separately  from  the  aorta, 
but  sometimes  they  arise  in  a common  trunk  which 
soon  divides.  In  some  instances  they  are  derived 
from  the  cceliac.  In  a few  cases,  the  aorta  furnishes 
one,  and  the  cceliac  the  other.  Each  of  the  phrenic 
arteries  commonly  crosses  the  crus  of  the  diaphragm 
on  its  respective  side,  and  proceeding  laterally,  in  a 
circular  direction,  often  ramifies  so  as  to  form  an  in- 


Distribution  of  the  Cceliac  Artery,  275 

ternal  and  external  branch.  Each  of  them  generally 
sends  branches  to  the  cardia  or  oesophagus,  to  the 
glandule  renales,  and  other  contiguous  parts. 

The  CCELIAC  Artery 

Is  the  first  great  branch  given  off  by  the  aorta  in  the 
abdomen,  and  is  distributed  almost  entirely' to  the  sto- 
mac h,  the  liver,  and  the  spleen.  It  projects  from  the 
anterior  part  of  the  aorta  so  as  to  form  a right  angle 
with  it,  and  is  of  course  nearly  horizontal,  when  the 
body  is  erect. 

The  main  trunk  of  this  great  artery  is  so  remarka- 
bly short,  that  it  has  been  compared  to  the  stump  of  a 
tree : for  at  the  distance  of  half  an  inch  from  its  origin, 
it  generally  divides  into  three  branches,  which  pass 
to  the  stomach,  the  liver,  and  the  spleen,  and  are, 
therefore,  denominated  the  Gastric  or  Coronary , the 
hepatic  and  the  splenic  arteries. 

The  first  mentioned  branch  may  be  called 

THE  SUPERIOR  CORONARY  OR  GASTRIC  ARTERY, 

To  distinguish  it  from  other  branches,  soon  to  be  de- 
scribed. It  is  commonly  in  the  centre  of  the  three 
great  ramifications  of  the  cceliac,  and  is  also  the 
smallest  of  them.  It  proceeds  from  its  origin  to  the 
upper  orifice  of  the  stomach  or  cardia,  and  continues 
thence  along  the  lesser  curvature  of  that  viscus,  until 
it  approaches  near  to  the  pylorus.  In  this  course  it 
sends  branches  to  the  oesophagus,  which  frequently 
inosculate  with  the  oesophageal  arteries.  It  also  fur- 
nishes branches  to  the  cardia,  which  partially  surround 
it ; and  on  this  account,  the  artery  has  been  called 
Coronary.  Some  of  these  last  mentioned  branches 
are  often  continued  on  the  great  extremity  of  the  sto- 
mach, and  anastomose  with  those  ramifications  of  the 
splenic  artery,  called  Vasa  Brevia . 

It  continues  on  the  lesser  curvature  between  the 


£76-  Distribution  of 

lamina  of  the  small  omentum*  and  sends  off  sueces- 
sively  branches  which  pass  between  the  peritoneal 
and  muscular  coats,  and  are  distributed  to  the  ante- 
rior and  posterior  surfaces  of  the  stomach,  communi- 
cating with  the  branches  of  the  inferior  gastric  arte- 
ries, soon  to  be  described.# 

THE  HEPATIC  ARTERY 

Proceeds  from  the  great  ramification  of  the  coeliac  to 
the  transverse  fissure  of  the  liver  called  the  Portse , in 
which  it  generally  divides  into  two  branches.  In  this 
course  it  very  frequently  sends  off  an  artery  to  the 
pylorus,  which  ramifies  about  the  small  extremity  of 
the  stomach,  and  often  inosculates  with  some  of  the 
branches  of  the  superior  coronary.  This  branch  is 
called  the  Pylorica,  and  sometimes  it  arises  from  the 
artery  next  to  be  mentioned. 

The  GASTRICA  INFERIOR  DEXTRA, 

Which  also  generally  originates  from  the  main  trunk 
of  the  hepatic,  but  sometimes  from  one  of  its  branches. 
It  is  an  artery  of  considerable  size,  which  proceeds 
along  the  great  curvature  of  the  stomach,  from  the 
pylorus  towards  the  great  extremity,  between  the 
lamina  of  the  anterior  portion  of  the  omentum,  and 
distributes  its  ramifications  to  both  sides  of  the  sto= 
maeh,  and  also  to  the  Omentum . In  its  progress 
from  the  hepatic  artery  to  the  stomach,  it  sends  off 
branches  to  the  Duodenum , and  to  the  right  end  of 
the  Pancreas . 

The  two  great  branches  into  which  the  hepatic 
artery  divides,  are  denominated  right  and  leftfivom 
the  lobes  of  the  viscus,  to  which  they  are  respective- 
ly appropriated.  The  right  branch  is  the  largest.— 

* This  artery  sometimes  sends  a branch  to  the  liver,  When  this  is  the 
’ease,  it  Ss  always  very  large 


277 


the  Splenic  Artery. 

Before  it  penetrates  the  substance  of  the  liver,  it 
sends  off  a branch  to  the  gall  bladder,  called  the 
Cystic  Artery . 

The  branches  of  the  hepatic  artery  ramify  very 
minutely  in  the  liver,  as  has  been  stated  in  the  ac- 
count of  that  organ. 

The  last  great  branch  of  the  coeliae  is 

The  SPLENIC  Artery , 

Which  is  generally  supposed  to  be  larger  than  the 
hepatic  in  adults,  although  it  is  less  in  children.  It 
proceeds  in  a transverse  direction  from  its  origin  to 
the  spleen : its  course  is  not  straight,  but  meandering 
or  serpentine.  It  is  situated  behind  and  above  the 
pancreas,  and  passes  along  the  groove  in  the  upper 
edge  of  that  viseus.  In  its  progress,  it  sends  off 
many  small  branches,  and  one  that  is  of  considerable 
size,  to  the  Pancreas.  It  also  sends  one  branch  to 
the  left  extremity  of  the  stomach,  which  arises  com- 
monly from  the  main  trunk,  but  sometimes  from  the 
ramifications,  which  are  soon  to  be  mentioned.  This 
branch,  which  is  called 

The  GASTRICA  INFERIOR  SINISTRA, 

Is  sometimes,  but  not  often  very  large : Its  course  is 
from  left  to  right.  It  is  situated  between  the  lami- 
na of  the  anterior  portion  of  the  omentum.  It  sends 
some  small  branches  to  the  omentum,  and  others 
which  are  larger  and  more  numerous,  to  both  sides 
of  the  stomach.  Some  of  these  last  mentioned  anas- 
tomose with  the  ramifications  of  the  gastrica  dextra, 
which  come  from  the  hepatic. 

When  the  splenic  artery  approaches  near  to  the 
spleen,  it  divides  into  four,  five,  or  six  branches 
each  of  which  penetrates  into  that  viseus  by  a dis* 


278  Distribution  of  the  Superior'  Mesenteric 

tinct  foramen,  and  then  ramifies  in  the  manner  de» 
scribed  in  the  account  of  the  structure  of  the  spleen.* 
Either  from  the  splenic  artery,  or  from  these  rami- 
fications,  four  or  five  branches  pass  to  the  large  extre* 
mity  of  the  stomach,  and  ramify  there,  communicating 
with  the  vessels  already  described.  These  arteries 
have  received  great  attention  from  physiologists,  and 
are  denominated  Vasa  Brevia . 

The  SURERIOR  MESENTERIC, 

Which  is  the  second  great  branch  given  off  in  the 
abdomen  by  the  aorta,  is  not  very  different  in  size, 
from  the  coeliac,  and  originates  about  half  an  inch 
below  it.  It  is  distributed  to  the  small  intestines  j 
to  that  portion  of  the  great  intestine,  which  is  situated 
on  the  right  side  of  the  abdomen ; and  to  the  arch  of 
the  colon.  From  its  origin  it  proceeds  downwards, 
under  the  pancreas,  and  over  the  lower  portion  of  the 
duodenum,  to  the  commencement  of  the  mesentery. 
When  it  has  arrived  between  the  lamina  of  that  mem- 
brane, it  descends  in  a direction  which  corresponds 
with  that  of  the  root  of  the  mesentery,  }-  and  forms  a 
gentle  curve,  with  its  convexity  directed  towards  the 
intestines.  It  necessarily  diminishes  as  it  descends, 
and  generally  terminates  by  anastomosing  with  one 
of  its  own  branches. — This  great  artery  sends  off 
some  very  small  ramifications  to  the  pancreas  and 
the  duodenum,  while  it  is  in  their  vicinity.  It  also 
sends  two  or  three  branches  to  the  transverse  part  of 
the  colon,  to  the  right  portion  of  the  colon,  to  the  be- 
ginning of  the  great  intestine,  and  the  contiguous 
portion  of  the  ileon.  These  branches  are  commonly 
termed  the  Colica  Media , Colica  Dextra , and  Ilco 

* It  frequently  happens  that  the  splenic  artery  divides  only  into  two  or 
three  branches,  and  they  subdivide  so  as  to  form  five  or  six,  which  pene- 
trate the  spleen. 

f Vol.  IT  p.  115, 


and  the  Inferior  Mesenteric  Arteries.  279 

Colica.  From  the  convex  side  of  the  curve,  the 
superior  mesenteric  sends  off  the  important 
branches  which  pass  between  the  lamina  of  the  me- 
sentery, and  supply  the  Small  Intestines.  These 
branches  are  numerous,  and  many  of  their  ramifica- 
tions anastomose  with  each  other  so  as  to  form 
arches.  From  these  arches  go  off  other  branches, 
which  anastomose  again  with  some  of  similar  origin; 
and  this  process  is  repeated  successively  several 
times,  so  that  a net-work  of  blood  vessels  seems  to 
be  formed  on  the  mesentery.  From  the  mesentery 
the  small  ramifications  are  continued  in  great  num- 
bers to  the  intestines.  Some  of  them  anastomose 
with  each  other  on  the  coats  of  the  intestine ; but  an 
immense  number  of  minute  arteries  are  continued  to 
thfe  villous  coat,  so  that,  when  they  are  successfully 
injected,  the  surface  of  that  coat  appears  uniformly 
coloured  by  the  injection.* 

The  INFERIOR  MESENTERIC  Artery 

Does  not  go  off  from  the  aorta  next  in  order  after  the 
superior  mesenteric,  but  succeeds  it  immediately  on 
the  intestines,  and  continues  the  arterial  ramifications 
to  the  left  portion  of  the  colon , to  which  the  branches 
of  the  superior  mesenteric  do  not  extend. 

This  artery  arises  between  the  origin  of  the  emul- 
gents  and  the  great  bifurcation  of  the  aorta,  and  pro- 
ceeds downwards,  inclining  to  the  left,  but  keeping 
near  to  the  aorta.  There  are  generally  three  branches 
distributed  to  the  left  portion  of  the  colon,  which  arise 
from  this  artery,  either  separately,  or  by  a common 
trunk  which  soon  divides.  It  frequently  happens, 
that  one  of  these  arteries  arises  separately,  and  two 
by  a common  trunk.  These  are  called  the  Left 

* See  the  account  of  the  termination  of  these  arteries,  at  page  110  of 
this  volypie. 


280  Emulgent  and  Capsular  Arteries. 

Colic  arteries;  and  are  also  sometimes  denominated, 
from  their  position,  Superior , Middle , and  Inferior . 
The  Superior  generally  anastomoses  with  that 
branch  of  the  superior  mesenteric,  which  is  called 
Colica  Media , and  forms  a remarkable  arch,  called 
the  Great  Mesocolic  Arch . The  ramifications  of  the 
other  branches  frequently  anastomose  with  each 
other,  and  are  finally  spent  upon  the  left  portion  of 
the  colon. 

The  main  trunk,  diminished  by  sending  off  these 
branches,  but  still  of  considerable  size,  runs  down- 
wards on  the  posterior  part  of  the  intestine  rectum, 
between  that  intestine  and  the  sacrum,  where  it  often 
divides  into  two  branches,  which  continue  near  to 
the  termination  of  the  rectum.  From  them  proceed 
many  ramifications  that  are  spent  upon  the  rectum. 
Some  of  these  ramifications  anastomose  with  each 
other,  and  others  with  the  ramifications  of  the  he- 
morrhoidal artery,  soon  to  be  mentioned. 

The  EMULGENT  or  RENAL  Arteries 

Are  the  large  vessels  which  pass  from  the  aorta  to 
the  kidneys.  They  arise  between  the  superior  and 
inferior  mesenteries,  one  on  each  side;  and  proceed 
in  a direction  which  is  nearly  reetangler  to  the 
aorta.  The  right  emulgent  artery  is  necessarily 
longer  than  the  left,  and  it  generally  passes  behind 
the  vena  cava.  When  they  approach  near  the  con- 
cave edges  of  the  kidneys,  each  emulgent  commonly 
divides  into  three  or  four  branches,  which  pass  into 
the  fissure  of  that  organ,  and  ramify  in  the  manner 
described  in  the  account  of  it.  Sometimes  two  arte- 
ries proceed  from  the  aorta  to  the  kidney : but  this 
is  not  a frequent  occurrence. 

The  Capsular  Arteries 

Are  the  small  vessels  which  pass  to  the  glandule 


2S1 


Adipose  and  Spermatic  Arteries. 

renales.  There  are  almost  always  several  of  them 
appropriated  to  each  gland.  They  often  arise  on 
each  side  from  the  coeliae  artery,  the  aorta,  and  the 
emulgent. 

The  Adipose  Arteries 

Supply  the  adipose  substance  surrounding  the  kid- 
neys.—There  are  several  of  them  on  each  side,  and, 
like  the  last  mentioned  arteries,  they  are  very  small, 
and  arise  from  several  sources  as  well  as  the  aorta. 
The  testicles  and  ovaria  are  supplied  by  the 

Spermatic  Arteries , 

Which  are  very  remarkable  for  their  great  length  and 
small  diameter.  In  a majority  of  cases  these  vessels 
arise  from  the  anterior  surface  of  the  aorta,  a little 
below  the  emulgents : but  it  often  happens  that  the 
left  spermatic  arises  from  the  emulgent  on  that  side. 
They  also  sometimes  arise  from  other  neighbouring- 
arteries.  It  has  been  observed  when  they  arise  from 
the  aorta,  that  the  origin  of  one  of  them  is  generally 
higher  than  that  of  the  other. 

They  pass  downwards,  so  as  to  form  an  acute  an- 
gle with  the  aorta,  and  proceed  behind  the  perito- 
neum, and  before  the  psoas  muscle  and  ureter.  While 
this  artery  is  in  contact  with  the  psoas  muscle,  it 
meets  with  the  ramifications  of  the  spei'matic  vein9 
and,  in  its  progress  to  the  abdominal  ring,  also  joins 
the  spermatic  cord.  In  this  course  it  sends  off  some 
very  small  twigs  to  the  contiguous  parts,  and  others 
that  anastomose  with  similar  ramifications  from  the 
mesenteric,  epigastric,  &c.  Before  it  arrives  at  the 
testicle,  it  divides  into  several  branches,  two  of  which 
generally  go  to  the  epididymis,  and  the  others  pene- 
trate the  upper  and  back  part  of  the  tunica  albuginea 
Yol,  ii,  36 


282 


Spermatic  Arteries. 


The  Spermatic  Arteries  in  the  Female , 

Instead  of  passing  to  the  abdominal  ring,  proceed  be- 
tween the  lamina  of  the  broad  ligaments,  and  send 
branches  to  the  ovaria,  which,  in  some  cases,  may  be 
traced  to  the  vesicles.  They  also  send  branches  to 
the  fallopian  tubes  and  uterus,  and  to  the  round  liga- 
ments. Those  which  are  on  the  opposite  sides  of  the 
uterus,  anastomose  with  each  other  and  with  the 
branches  of  the  hypogastric  arteries. 

The  lumbar  regions  are  supplied  with  arteries 
which  originate,  like  the  intercostals,  from  the  poste- 
rior part  of  the  aorta  between  the  thorax  and  pelvis. 
There  are  four  or  five  of  these  vessels  on  each  side, 
and  they  are  denominated 

The  Lumbar  Arteries . 

They  pass  between  the  spine  and  the  psoas  muscles, 
and  send  branches  to  the  spinal  cavity,  to  the  muscles 
of  the  lumbar  regions,  and  the  abdominal  muscles. 
They  anastomose  with  the  internal  mammary,  the 
epigastric,  the  circumflex  of  the  ilium,  &c. 

A small  artery  passes  off  singly  from  the  posterior 
part  of  the  aorta  at  its  bifurcation,  which  is  called 

The  Middle  Sacral  Artery. 

It  proceeds  down  the  middle  of  the  sacrum  to  the  os 
coccygis,  and  sends  off  lateral  branches,  which  are 
spent  upon  the  contiguous  parts,  and  inosculate  with 
the  arterice  sacra}  laterales.. 


General  Account  of  the  Internal  Iliac.  283 


SECTION  IV. 

Of  the  Arteries  which  originate  at  and  below  the 
Great  Bifurcation  of  the  Aorta. 

The  PRIMITIVE  ILIACS 

Form  an  acute  angle  with  each  other.  They  proceed 
downwards  behind  the  peritoneum,  very  near  the 
margin  of  the  pelvis,  without  sending  off  any  branch 
of  importance.  At  the  junction  of  the  sacrum  with 
the  ossa  ilea,  they  divide  into  two  great  branches  : 
the  internal  iliac,  or  hypogastric,  which  de- 
scends into  the  pelvis ; and  the  external  iliac, 
which  passes  under  the  crural  arch  to  the  lower  ex- 
tremity. 

The  INTERNAL  ILIAC,  or  HYPOGASTRIC, 

Is  distributed,  in  part,  to  the  viscera  of  the  pelvis  and 
the  organs  of  generation,  and  also  to  the  large  mus- 
cles exterior  to  the  pelvis : it  is,  therefore,  very  large, 
although  not  quite  equal  to  the  external  iliac. 

It  has  already  been  mentioned,  that  in  the  foetal 
state,  this  vessel  appeared  to  continue  in  a curved 
direction  from  its  origin  to  the  lower  part  of  the  side 
of  the  bladder,  and  from  thence  to  the  Umbilicus, 
under  the  denominations  of  the  Umbilical  Artery. 
From  the  convex  side  of  this  curve  the  different 
branches  of  the  internal  iliac  go  off.  In  the  foetal 
state  they  are  very  small,  in  proportion  to  the  umbi- 
lical artery ; but  as  the  artery  becomes  ligamentous, 
these  branches  increase  in  size. 

In  the  adult,  the  arrangement  of  these  vessels  is 
very  different.  The  internal  iliac  generally  di- 
vides into  two  great  branches:  the  Gluteal,  which 
passes  through  the  sacro  sciatic  notch,  and  ramifies 


5384  Smaller  Branches  of  the  Internal  Iliac. 

on  the  exterior  and  upper  part  of  the  os  ilium  : and 
the  Ischiatic,  which  passes  downwards  on  the  outside 
of  the  tuberosity  of  the  ischium. 

The  first  of  these  large  ramifications  passes  out  of 
the  pelvis  above  the  pyriform  muscle,  and  the  last 
of  them  below  it.  Several  smaller  arteries  arise  from 
these  branches  near  their  origin,  or  from  the  main 
trunk  of  the  internal  iliac,  which  are  distributed  to 
the  different  parts  of  the  pelvis;  and  one  important 
•branch  of  the  ischiatic,  called  the  Pudic,  proceeds 
downward  on  the  inside  of  the  tuberosity  of  the  is- 
chium. 

The  first  of  the  smaller  branches  which  the  inter- 
nal iliac  commonly  sends  off,  is  called  the 

Ileo  Lumbalis  : 

It  sometimes  arises  from  the  gluteal  artery,  and 
sometimes  from  the  main  trunk  of  the  internal  iliac. 
It  passes  outwards  under  the  psoas  muscle,  and  sud- 
denly divides  into  two  branches.  One  of  them  pro- 
ceeds upwards,  and  is  distributed*  in  the  lumbar  re- 
gion, while  the  other  ramifies  on  the  illacus  internus 
muscle,  and  is  spent  on  the  contiguous  parts. 

There  are  also  two  or  three  small  arteries  called 

Jlrteria  Sacrse  Later  ales* 

v 

Which  \sometimes  arise  singly,  and  sometimes  in 
common,  from  the  great  trunk.  They  also  occa- 
sionally originate  from  the  gluteal  artery.  These 
vessels  enter  the  anterior  foramina  of  the  os  sacrum, 
to  be  distributed  on  the  cauda  equina  and  the  mem- 
branes which  invest  it.  Some  of  their  ramifications 
anastomose  with  branches  of  the  sacra  media  and 
other  contiguous  arteries. 

On  the  anterior  side  of  the  internal  iliac,  near  the 
origin  of  the  above  mentioned  vessels,  a ligament 
which  was  originally  the  umbilical  artery,  goes  off 


Smaller  Branches  of  the  Internal  Iliac:  §8 5 

to  the  side  of  the  bladder,  and  continues  from  thence 
to  the  umbilicus.  Sometimes  it  continues  pervious 
for  a short  distance,  and  then  small  branches  pass 
from  it  to  the  bladder. 

In  the  female  it  also  sends  small  branches  to  the 
uterus  and  vagina. 

In  addition  to  these  Vesical  Arteries  derived  from 
the  umbilicals,  there  are  other  branches  distributed 
to  the  bladder,  which  arise  very  differently,  in  dif- 
ferent subjects,  from  branches  which  are  soon  to  be 
described,  as  the  hsemorrhoidal,  pudic,  &e. 

From  the  anterior  side  of  the  internal  iliac,  or  from 
one  of  its  great  branches,  an  artery  often  arises  which 
passes  out  of  the  pelvis  through  the  aperture  in  the 
margin  of  the  ligamentous  membrane  which  closes 
the  foramen  thyroideum  of  the  os  innominatum  : this 
is  called  the 

Obturator  Artery . 

This  vessel,  while  it  is  in  the  pelvis,  often  sends 
small  branches  to  the  bladder  and  its  appendages,  and 
to  the  obturator  internus  muscle.  After  it  passes  out 
of  the  pelvis,  it  frequently  divides  into  branches  ; 
some  of  which  are  spent  on  the  obturator  externus, 
and  the  contiguous  muscles,  and  others  go  to  the  hip 
joint.  The  origin  of  this  artery  is  variable.  Most 
commonly  it  arises  from  the  internal  iliac,  but  often 
from  the  ischiatic,  and  sometimes  from  the  gluteal. 
In  some  instances  it  originates  in  a way  that  is  par- 
ticularly interesting  when  the  operation  for  crural 
hernia  is  to  be  performed,  viz.  from  the  epigastric 
artery,  soon  to  be  described  : for  in  this  case  the  ob- 
turator artery  sometimes  nearly  surrounds  the  neck 
of  the  hernial  sac.* 

See  Astley  Cooper’s  great  work  on  Hernia,  Vol.  I. 

There  is  reason  to  believe  that  this  position  of  the  artery  occurs  more 
frequently  than  has  been  supposed. 


286  Larger  Branches  of  the  Internal  Iliac. 

A small  artery  passes  from  the  internal  iliac  or 
one  of  its  branches,  to  the  rectum,  which  is  called 
the 

Middle  Hsemorrhoidal, 

From  its  situation  between  the  branches  which  are 
sent  to  that  intestine  from  the  inferior  mesenteric, 
and  those  which  go  to  it  from  the  pudic.  This  arte- 
ry is  spent  upon  that  part  of  the  rectum,  which  is 
above  and  in  contact  with  the  sphincter.  It  sends 
branches  to  the  prostate  and  vesiculte  seminales  in 
males,  and  the  vagina  and  bladder  in  females. 

In  females  there  is  a peculiar  artery,  ■ 

The  Uterine , 

Which  originates  either  from  the  internal  iliac,  near 
the  origin  of  the  ischiatic,  or  from  one  of  its  branches. 
It  passes  between  the  lamina  of  the  broad  ligaments 
to  the  cervix  uteri,  and  penetrates  the  texture  of  that 
organ.  The  size  of  this  vessel  varies  with  the  vary- 
ing size  of  the  uterus. 

The  gluteal  or  posterior  iliac  Artery , 

One  of  the  two  great  branches  of  the  internal  iliac, 
proceeds  exteriorly  through  the  sciatic  notch  above 
the  pyriform  muscle,  very  near  the  edge  of  the  bone. 
On  the  outside  of  the  ilium  it  generally  divides  into 
two  branches,  one  of  which  ramifies  between  the 
gluteus  medius  and  minimus,  and  the  other  between 
the  medius  and  maximus.  It  is  principally  spent 
upon  these  muscles,  and  sends  branches  to  the  conti- 
guous parts. 

The  ischiatic  Artery , 

The  other  great  branch  of  the  internal  iliac,  passes 
through  the  sciatic  notch  below  the  pyriform  muscle, 
and  proceeds  downwards,  between  the  great  tro- 
chanter of  the  os  femoris  and  the  tuberosity  of  the 
ischium,  under  the  gluteus  maximus  muscle.  Soon 


287 


Pndic  Artery* 

after  its  orgin,  it  commonly  sends  off  a considerable 
branch,  the  Arteria  Pudica , which  also  passes  down- 
wards : it  then  continues  its  course  as  above  mention- 
ed, and  its  principal  branches  are  distributed  to  the 
gluteus  maximus  and  the  muscles  of  the  upper  and 
back  part  of  the  thigh,  while  its  smaller  branches  go 
to  the  os  sacrum  and  coccyx,  and  the  contiguous 
small  muscles. 

The  PUDICA  INTERNA, 

As  has  been  just  mentioned,  is  often  a branch  of  the 
ischiatic  artery,  but  sometimes  originates  immediately 
from  the  internal  iliac.  It  proceeds  downwards  and 
inwards,  diverging  from  the  ischiatic,  and  passing  be= 
tween  the  two  sacro-sciatic  ligaments  to  the  interior 
side  of  the  tuberosity  of  the  ischium,  whence  it  con- 
tinues on  the  inside  of  the  crus  of  the  os  ischium  and 
pubis  until  it  approaches  the  symphisis,  when  it  gen- 
erally  divides  into  three  branches,  which  are  spent 
upon  the  organs  of  generation,  from  which  circum- 
stance the  name  of  this  artery  is  derived. 

One  or  more  branches  from  it  also  pass  to  the  low- 
er part  of  the  rectum  and  sphincter  ani,  and  are  call- 
ed the  Lower  Hsemorrhoidal  Arteries . 

In  its  course  it  sends  off  many  small  branches  to 
the  contiguous  parts ; one  of  which,  called  the  Pfli 
neal,  leaves  it  near  the  transversus  perinei,  and  passes 
between  that  muscle  and  the  skin,  and  between  the 
bulb  of  the  urethra  and  the  crus  of  the  penis,  to  the 
scrotum. 

When  the  Pudic  has  arrived  near  the  bulb  of  the 
urethra  it  sends  a branch  into  it,  which  is  continued 
into  the  corpus  spongiosum  urethras,  and  ramifies 
there  minutely. 

At  the  symphisis  of  the  pubis,  it  sends  off  a second 
branch,  which  passes  to  the  back  of  each  crus,  and, 
proceeding  along  it,  parallel  to  its  fellow,  terminates 


288  External  Iliac. — Branches  of  the  External  Iliac , 

in  the  glans  penis:  in  this  course  it  sends  branches  to 
the  elastic  coat,  to  the  integuments,  and  to  the  pre- 
puce. This  vessel  is  called  the  Arteria  Dorsalis. 

The  main  trunk  of  the  pudic  artery  then  penetrates 
the  corpus  cavernosum,  and  proceeds  through  it  in  a 
straight  direction.  Its  ramifications  appear  to  be  dis- 
tributed through  the  internal  structure  of  the  corpus 
cavernosum,  and  some  of  them  extend  through  the 
septum  to  the  other  side,  while  others  pass  to  the 
corpus  spongiosum  urethrze. 

The  EXTERNAL  ILIAC, 

The  great  artery  of  the  lower  extremity,  appears 
soon  after  birth,  like  a continuation  of  the  primitive 
iliac,  and  proceeds  along  the  brim  of  the  pelvis  be- 
hind the  peritoneum,  to  Poupart’s  ligament  or  the 
crural  arch,  under  which  it  passes. 

The  psoas  muscle  is  at  first  in  contact  with  it  on 
the  outside,  and  the  internal  iliac  vein  on  the  inside. 
As  it  passes  under  PouparPs  ligament,  it  is  immedi- 
ately anterior  to  the  psoas  and  iliacus  internus  mus- 
cles where  they  are  united,  and  the  crural  nerve  is 
exterior  to  it.  Before  it  arrives  at  the  lower  edge 
of  PouparPs  ligament,  it  sends  off 

The  Epigastric  Artery. 

Which  arises  on  its  internal  side,  and  proceeds  down- 
wards and  inwards  about  half  an  inch,  then  it  turns 
upwards  and  inwards,  and  continues  in  that  direction 
for  a small  distance,  after  which  its  course  is  less  ob- 
lique. It  passes  between  the  peritoneum  and  the  ab- 
dominal muscles,  behind  the  spermatic  cord,  and  the 
round  ligaments  in  females. 

It  generally  changes  its  oblique  direction  after 
passing  about  two  inches,  and  then  proceeds  in  con-- 


General  Account  of  the  Femoral  Artery . 289 

£act  with  the  rectus,  and  very  near  its  external  edge. 
Its  ramifications  are  expended  upon  the  anterior  pa- 
rietes  of  the  abdomen  ; and,  after  it  has  arrived  as 
high  as  the  umbilicus,  it  commonly  divides  into 
branches,  which  often  inosculate  with  the  ramifica- 
tions of  the  internal  mammary.* 

An  artery,  which  is  rather  smaller  than  the  epigas- 
tric, arises  nearly  opposite  to  it,  but  rather  lower, 
from  the  external  side  of  the  external  iliac.  It  is 
called 

The  Circumflex  Artery  of  the  Os  Ilium , 

And  proceeds  upwards  and  outwards  to  the  upper 
margin  of  the  os  ilium,  along  which  it  continues  very 
near  to  the  spine.  It  is  distributed  principally  to 
the  abdominal  muscles,  to  the  iliacus  internus  and  the 
psoas,  and  the  parts  contiguous. 

The  artery  of  the  lower  extremity,  after  passing 
under  PouparPs  ligament,  takes  the  name  of 

FEMORAL  Artery , 

And  proceeds  downwards  in  a direction  so  spiral, 
that  although  it  is  in  front  at  the  upper  part  of  the 
thigh,  it  is  completely  behind  at  the  lower  part.  It 
sends  branches  to  the  muscles  of  the  thigh,  as  the 
aorta  does  to  the  viscera  of  the  abdomen,  viz.  by  a 
few  large  vessels  which  extend  and  ramify  to  a great 
distance  among  them. 

The  situation  of  the  abductor  muscles,  and  their 
attachment  to  the  os  femoris,  is  such,  that  the  artery 
in  this  course  must  necessarily  perforate  their  com- 

* Several  respectable  surgeons  have  been  taught  by  experience,  that 
when  the  abdomen  is  distended  by  ascites,  the  position  of  the  epigastric 
artery  is  so  much  altered,  that  it  will  sometimes  be  found  in  the  middle  of 
the  oblique  line,  which  extends  from  the  umbilicus  to  the  superior  anterior 
spine  of  the  ilium, 

VOL,  II, 


3? 


290  Branches  of  the  Profunda  and  the  Femoral . 

mon  tendon,  which  it  does  at  the  distance  of  one- 
third  of  the  length  of  the  bone  from  its  lower  end. 
The  aperture  in  this  tendon  corresponds  precisely 
with  the  general  course  of  the  artery ; and  before 
the  artery  enters  this  perforation,  it  is  on  the  inter- 
nal side  of  the  bone ; after  it  has  passed  the  perfo- 
ration, it  is  on  the  posterior  side  of  it.  After 
passing  through  the  tendon  of  the  abductors,  it  is 
denominated  The  Popliteal  Artery,  and  it  retains 
this  name  until  it  divides. 

It  then  proceeds  downwards,  being  very  near  the 
bone,  and  between  the  tendons  of  the  flexors  of  the 
leg,  covered  by  the  great  nerve  of  the  lower  extre- 
mity, and  very  often  also  by  the  vein.  After  cross- 
ing the  articulation  of  the  knee,  when  it  is  between 
the  heads  of  the  gastrocnemii  muscles,  at  the  lower 
edge  of  the  popliteus  muscle,  it  divides  into  the  an- 
terior tibial  and  the  common  trunk  of  the  peroneal 
and  posterior  tibial  arteries. 

The  femoral  artery,  soon  after  emerging  from 
Poupart’s  ligament,  sends  off  very  small  branches  to 
the  inguinal  glands,  and  other  contiguous  parts.  It 
also  sends  off  the 

External  Pudics , 

Which  are  two  or  three  small  arteries  that  are  gene- 
rally spent  upon  the  Scrotum  in  males,  and  the  Labia 
Pudendi  in  females. 

About  two  inches  below  Poupart’s  ligament,  the 
great  branch  which  has  been  called  the  muscular 
artery  of  the  thigh,  leaves  it.  This  vessel  is  com- 
monly denominated 

ARTERIA  PROFUNDA. 

It  arises  from  the  baek  part  of  the  trunk  of  the  femo- 
ral, and  passes  downwards  and  backwards,  in  a way 
that  has  been  compared  to  the  separation  of  the  in» 


Branches  of  the  Prof  unda  and  the  Femaral.  291 

ternal  iliac  from  the  external.  Very  soon  after  its 
origin,  it  sends  off  two  branches,  which  proceed,  one 
on  the  internal,  and  the  other  on  the  external  side  of 
the  thigh,  and  are  called  the  circumflexa  interna  and 
externa.  It  then  passes  downwards  behind  the  trunk 
of  the  femoral,  and  sometimes  very  near  it,  on  the 
adductor  muscles,  and  finally  divides  into  branches, 
which  are  called  the  Perforating. 

The  External  Circumflex 

Sometimes  arises  from  the  femoral,  but  most  common- 
ly is  a branch  of  the  profunda,  as  above  stated.  It 
passes  under  the  rectus  and  tensor  vaginse  femoris 
towards  the  great  trochanter,  and  generally  divides 
into  two  branches,  one  of  which  continues  in  the 
transverse  direction,  and  sends  branches  to  the  upper 
and  back  part  of  the  thigh,  and  the  parts  contiguous 
to  the  joint ; while  the  other  descends  in  the  course 
of  the  rectus  femoris  muscle,  and  some  of  its  ramifi- 
cations extend  near  to  the  outside  of  the  knee. 

The  Internal  Circumflex 

Is  often  smaller  than  the  other.  It  generally  passes 
between  the  psoas,  and  the  pectineus  muscles,  and 
continues  round  the  thigh  towards  the  lesser  trochan- 
ter. Its  ramifications  are  expended  on  the  upper  por- 
tions of  the  adductor  muscles  and  the  muscular  parts 
contiguous  to  the  lesser  trochanter.  It  also  sends 
branches  to  the  articulation. 

The  Perforating  Arteries 

Are  two  or  three  ramifications  of  the  profunda,  which 
pass  through  the  adductor  muscles,  and  are  expended 
upon  the  flexor  muscles  on  the  back  of  the  thigh. 
Some  of  the  terminating  branches  of  the  profunda 
itself  are  also  called  perforating  arteries. 

The  next  branch  of  importance  which  is  sent  off 


292 


Branches  about  the  Ham . 


by  the  femoral  artery,  leaves  it  before  it  enters  the 
aperture  in  the  tendon  of  the  adductors,  and  is  called 
The  Anastomotic  Artery. 

This  vessel  soon  inclines  downwards.  Its  ramifica- 
tions extends  into  the  vastus  internus  muscle  ; some 
of  them  follow  the  tendon  of  the  adductors,  and  ram- 
ify about  the  internal  condyle. 

Several  small  branches  go  off  from  the  great  artery 
soon  after  it  passes  though  the  tendon  of  the  adduc- 
tors, which  are  distributed  to  the  contiguous  mus- 
cles. Some  of  them  are  also  called 

Perforating  Arteries. 

Among  them  is  the  principal  Medullary  artery  of  the 
os  femoris. 

In  the  ham,  the  great  vessel  there  called 
POPLITEAL, 

generally  sends  ofF  several  small  branches.  Two  of 
them  go  off  orf  the  inside,  one  above  and  the  other 
below  the  knee ; and  two  on  the  outside  in  the  same 
manner.  They  are  named,  from  their  situation,  The 
Superior  and  Inferior  Internal , and  The  Superior 
and  Inferior  External  Articulary  Arteries. 

The  Superior  Internal  artery  perforates  the  ten- 
don of  the  adductors  above  the  internal  condyle,  and 
ramifies  minutely  on  the  inner  side  of  the  joint. 

The  Superior  External  artery  passes  through  the 
lower  portion  of  the  biceps  above  the  external  condyle, 
and  ramifies  minutely  on  the  outer  side  of  the  joint. 
Its  superior  ramifications  anastomose  with  those  of 
the  descending  branch  of  the  external  circumflex, 
while  its  inferior  ramifications  communicate  with 
those  of  the  corresponding  artery  below. 

The  two  inferior  arteries  originate  nearly  opposite 
to  the  middle  of  the  joint,  and  pass  downwards. 

The  Inferior  Internal  artery  passes  under  the 


293 


Artery  of  the  Leg. 

internal  head  of  the  gastrocnemius  muscle,  on  the 
posterior  and  internal  side  of  the  head  of  the  tibia. 
Its  ramifications  communicate  with  those  of  the  cor- 
responding artery  above  and  of  the  tibialis  antiea.-=- 
Below  they  also  extend  to  the  interior  of  the  joint. 

The  Inferior  External  artery  passes  under  the 
external  head  of  the  gastrocnemius  and  the  plantaris 
muscle,  and  continues  under  the  external  lateral  and 
the  capsular  ligament.  It  is  distributed  on  the  ex- 
ternal and  inferior  part  of  the  articulation,  and  sends 
also  some  branches  to  the  interior  of  the  joint. 

There  is  frequently  an  azygous  vessel,  called  the 
Middle  Articular  artery,  which  arises  from  the  back 
of  the  popliteal,  and  is  distributed  to  the  posterior 
part  of  the  articulation. 

The  popliteal  artery,  after  this,  sends  off  a few 
small  branches  to  the  heads  of  the  muscles  of  the  leg, 
and  among  them  one  of  considerable  length,  to  each 
of  the  heads  of  the  gastrocnemii.  At  the  under 
edge  of  the  popliteus  muscle,  it  sends  off  horizon- 
tally a large  branch  which  passes  directly  forward 
between  the  tibia  and  fibula,  above  the  commence- 
ment of  the  interosseous  ligament.  After  this  it  con- 
tinues to  descend,  nearly  in  the  same  direction,  un- 
der the  soieus  muscle,  behind  the  tibia ; but  before 
it  has  proceeded  further  than  twelve  or  fifteen  lines, 
it  sends  off  a branch  which  forms  an  acute  angle  with 
it,  and  approaches  near  the  fibula,  along  which  it  de- 
scends. 

The  branch  sent  off  anteriorly,  is  called  the  Ante- 
rior Tibial  artery. 

The  main  trunk,  which  continues  downwards,  is 
called  the  Posterior  Tibial  artery ; 

And  the  branch  which  descends  near  the  fibula  is 
called  the  Peroneal  or  Fibular  artery. 


294 


Anterior  Artery  of  the  Leg . 


The  anterior  tibial  Artery , 

After  its  arrival  on  the  anterior  part  of  the  leg,  pass= 
es  down  close  to  the  interosseous  ligament,  with  the 
tibialis  anticus  muscle  on  the  inside,  and  the  extensor 
communis  on  the  outside,  in  the  first  part  of  its 
course;  and  afterwards,  with  the  extensor  pollicis 
pedis  on  the  outside  of  it.  It  gradually  inclines  in* 
ternally  as  it  descends,  so  that  a little  above  the  ankle 
it  is  upon  the  front  part  of  the  tibia.  It  proceeds 
thence  with  the  tendons  of  the  extensor  digitorum 
pedis,  under  the  annular  ligament,  to  the  upper  sur- 
face  of  the  foot,  on  which  it  continues  to  the  inter- 
stice of  the  first  and  second  metatarsal  bones,  where 
it  descends  to  anastomose  in  the  way  presently  to  be 
mentioned. 

In  this  course  it  sends  off,  soon  after  it  has  arrived 
at  its  anterior  situation,  a recwrent  branch,  which 
Is  distributed  to  the  heads  of  the  muscles  and  the 
ligaments  of  the  articulation,  and  which  anastomoses 
with  the  branches  of  the  inferior  articular  arteries. 
It  also  sends  off,  on  each  side,  many  arterial  twigs 
to  the  contiguous  muscles,  and  very  frequently  one 
branch  of  considerable  size,  which  passes  down  near 
the  fibula. 

When  it  has  arrived  near  the  end  of  the  tibia,  it 
sends  a branch  on  each  side,  called  the  Internal  and 
External  Malleolar.  On  the  top  of  the  foot,  among 
several  smaller  arteries,  it  sends  off  a branch  under 
the  extensor  brevis  digitorum  pedis,  which  passes  out- 
wards and  forwards,  and  supplies  the  muscles,  &c. 
on  the  upper  part  of  the  foot.  This  vessel  is  called 
Arteria  Tarsea.  There  is  also  another  branch,  call- 
ed Metatarsea,  which  generally  arises  about  the  mid- 
dle of  the  foot,  and  passes  obliquely  outward  and  for- 
ward, supplying  the  contiguous  parts. 


Posterior  Tibicil  and  Peroneal  Arteries.  295 

The  Anterior  Tibial  artery,  having  arrived  at  the 
space  between  the  metatarsal  bones  of  the  first  and 
second  toes,  bends  down  to  the  sole  of  the  foot,  but 
previously  sends  off  a branch  which  passes  near  the 
external  edge  of  the  metatarsal  bone  of  the  great  toe, 
and  divides  into  two  branches,  one  of  which  goes  to 
the  outside  of  the  great  toe,  and  the  other  to  the  op- 
posite  side  of  the  toe  next  to  it. 

The  posterior  tibial  Artery , 

After  sending  off  the  anterior  tibial,  parts  with  the 
Peroneal  or  Fibzilar,  as  has  been  already  stated,  and 
then  continues  on  the  back  of  the  tibia,  behind  the 
internal  ankle,  to  the  sole  of  the  foot. 

The  Peroneal  or  Fibalar  Artery 

Is  not  commonly  so  large  as  either  of  the  two  other 
arteries  of  the  leg,  nor  is  it  so  constant.  It  passes 
down  very  near  the  internal  edge  of  the  fibula.  It 
is  in  contact,  for  some  distance,  with  the  tibialis  pos- 
ticus muscle,  and  is  anterior  to  the  soleus  and  the 
flexor  pollicis  longus ; it  sends  branches  to  the 
contiguous  muscles.  After  it  has  passed  along  two- 
thirds  of  the  length  of  the  fibula,  it  frequently,  but 
not  always,  divides  into  an  anterior  and  a posterior 
branch. 

The  anterior  peroneal  soon  perforates  the  interos- 
seous ligament,  and  passing  down  some  distance  on 
its  anterior  surface,  continues  to  the  ankle  and  upper 
surface  of  the  foot.  It  gives  ramifications  to  all  the 
contiguous  parts  in  its  progress,  and  anastomoses 
with  some  of  the  small  ramifications  of  the  tibialis 
antica. 

The  posterior  peroneal  branch  is  the  continuation 
of  the  main  trunk.  It  passes  behind  the  external 
malleolus,  and  ramifies  upon  the  external  side  of  the 
foot. 


296 


Arteries  of  the  Foot . 

The  posterior  tibial  artery  passes  down,  inclining 
rather  obliquely  inwards,  between  the  gastrocne- 
mius internus,  which  is  posterior  to  it,  and  the  tibia- 
lis posticus  and  flexor  digitorum,  which  are  anterior 
to  it.  Upon  the  leg  it  gives  off  many  small  branches, 
one  of  which,  termed  the  Arteria  JVutriiia  Tibise9 
comes  off  high  up,*  and,  after  ramifying  as  it  de- 
scends, sends  a branch  to  the  medullary  foramen  of 
the  tibia. 

At  the  lower  part  of  the  leg  the  Posterior  Tibial , 
is  situated  rather  superficially  between  the  tendo 
Achillis  and  the  tibia.  It  proceeds  thence  behind 
the  internal  ankle  in  a deep  situation,  covered  by  an 
annular  ligament,  and  passes  between  the  abductor 
muscle  of  the  great  toe  and  the  bones  of  the  tarsus. 
It  then  divides  into  two  branches— the  internal  and 
the  external  plantar  arteries. 

The  Internal  Plantar  Artery 

Is  commonly  much  smaller  than  the  other  ramifica- 
tion. It  passes  in  the  direction  of  the  internal  edge 
of  the  foot,  but  at  some  distance  from  it,  and  often 
lies  between  the  aponeurosis  plantaris  and  the  ab- 
ductor pollicis.  It  frequently  terminates  by  anasto- 
mosing with  one  of  the  arteries  of  the  great  toe,  and 
in  its  course  sends  off  several  branches  to  the  conti- 
guous parts  on  each  side  of  it. 

The  External  Plantar  Artery 

Is  the  continuation  of  the  main  trunk.  It  proceeds 
outwards  and  forwards  between  the  short  flexor  of 
the  toes  and  the  flexor  accessorius;  and  continues 
afterwards  between  the  first  of  these  muscles  and  the 
abductor  of  the  little  toe.  At  the  metatarsal  bone  of 


* This  artery  sometimes  comes  off  from  the  popliteal. 


297 


Arteries  of  the  Foot . 

the  little  toe  it  begins  to  curve,  and  continues  its  cur- 
vature across  the  other  metatarsal  bones  to  the  inter- 
stice between  the  great  toe  and  the  one  next  to  it, 
passing  between  the  tendons  of  the  long  extensor  and 
the  metatarsal  bones.  At  the  interstice  above  mention- 
ed, it  anastomoses  with  the  tibialis  antica.  The  cur- 
vature, thus  formed,  is  called  the  Arcus  Plantar  is. 

In  this  course,  the  External  Plantar  sends  off  se- 
veral branches,  to  the  heel  and  the  parts  of  the  foot, 
especially  on  the  external  side;  the  deep-seated  parts 
of  the  foot  being  supplied  from  the  eurve. 

Digital  branches  go  off  from  the  curve,  as  they  do 
in  the  hand,  from  the  curve  of  the  ulnar.  There  is 
first  a small  branch  to  the  outside  of  the  little  toe ; 
and  then  three  regular  branches,  which  pass  to  the 
junction  of  the  roots  of  the  four  small  toes,  and  divide, 
like  the  digital  arteries  of  the  hand,  so  as  to  send  a 
branch  to  the  side  of  each  toe.  These  digital  arteries 
pass  between  the  muscle  called  Transversalis  Pedis 
and  the  metatarsal  bones.  Near  the  heads  of  these 
bones,  each  of  them  generally  sends  off  two  arteries 
that  pass  upwards  between  the  interossei  muscles  and 
the  bones,  and  anastomose  with  the  ramifications  from 
the  top  of  the  foot. 

The  External  Plantar , soon  after  sending  off  the 
third  digital  artery,  anastomoses  with  the  anterior 
tibial,  and  then  continues  to  the  junction  of  the  root 
of  the  great  toe  with  the  one  next  to  it,  when  it  di- 
vides into  two  branches,  which  go  to  the  opposite 
sides  of  those  toes.  In  its  course  it  also  sends  a branch 
to  the  internal  side  of  the  great  toe. 


38 


VOL.  II. 


CHAPTER  III. 


OF  THE  PARTICULAR  DISTRIBUTION  OF  THE  VEINS. 

Anatomists  of  great  respectability  have  very  dif- 
ferent sentiments  respecting  the  best  method  of  de- 
scribing the  veins.  Some  of  them,  in  order  to  follow 
the  course  of  the  circulation,  commence  with  the  small 
veins,  and  proceed  to  the  large  trunks  which  are 
formed  by  their  union.  Others  begin  with  the  great 
veins  that  empty  into  the  heart,  and  proceed  from 
them  to  the  small  ramifications  of  the  venous  system, 
in  a direction  the  reverse  of  the  circulation. 

As  the  last  method  is  the  easiest  for  the  student  of 
anatomy,  it  will  be  adopted  here  ; but  it  must  always 
be  kept  in  mind,  that  the  blood  flows  from  the  small 
veins  into  the  larger,  and  not  from  the  latter  into  the 
former,  as  the  mode  of  description  seems  to  imply. 

The  great  trunk  of  the  venous  system  differs  con- 
siderably  from  that  of  the  arterial  with  respect  to 
its  connexion  with  the  heart ; for  it  communicates 
with  that  organ  in  such  a manner  that,  when  viewed 
from  before,  it  appears  like  two  vessels  ; one  open- 
ing into  the  upper,  and  the  other  into  the  lower  part 
of  the  right  auricle.  When  viewed  from  behind,  it 
appears  like  a continued  tube,  three-fourths  of  which 
are  deficient  anteriorly ; and  to  the  margin  of  this 
deficiency  the  right  sinus  or  pouch  of  the  heart  is 
connected. 

In  some  preparations  of  the  heart,  where  all  the 
great  vessels  connected  with  it  are  much  distended 
by  the  injection,  and  the  pulmonary  vessels  are  in- 


299 


The  Feins  of  the  Heart. 

jected  first,  the  right  auricle  is  so  much  pressed 
upon  from  behind,  by  the  vessels  which  go  to  the 
right  lung,  that  the  direction  of  the  superior  and  in- 
ferior portions  of  the  vena  cava,  which  thus  commu- 
nicate with  it,  is  altered.  Each  of  them  is  turned 
obliquely  forwards,  so  that  it  forms  an  angle  with 
the  other.  This  occasions  them  to  appear  more  like 
distinct  vessels  than  they  otherwise  would  do. 

The  above  mentioned  portions  of  the  great  veins 
are  denominated  the  Superior  or  Descending , and  the 
Inferior  or  Ascending  Vena  Cava  ,*  as  if  they  were 
perfectly  distinct  and  unconnected  with  each  other. 

The  coronary  Veins. 

Which  are  exclusively  appropriated  to  the  heart, 
may  be  considered  here,  as  they  are  not  included  in 
the  general  arrangement  of  the  veins. 

The  great  vein  of  the  heart  begins  at  the  lower 
part  of  the  right  auricle,  very  near  to  the  septum, 
which  divides  the  two  auricles.  It  soon  proceeds  to 
the  left  in  a circular  direction,  surrounded  with  adi- 
pose matter,  in  the  deep  groove  which  exists  between 
the  left  auricle  and  the  left  ventricle.  It  continues 
between  the  auricle  and  ventricle,  until  it  is  imme- 
diately over  the  septum,  which  divides  the  two  ven- 
tricles. Here  its  direction  changes,  and  it  proceeds 
to  the  apex  of  the  heart,  where  its  small  ramifications 
anastomose  with  others  soon  to  be  described.  In  its 
course  round  the  basis  of  the  left  ventricle,  it  sends 
off  several  branches,  one  of  which  is  considerable, 
that  proceed  from  the  basis  towards  the  apex  of  the 
heart,  ramifying  on  the  surface  of  the  left  ventricle. 

A second  vein,  much  less  than  the  first,  appears 
to  proceed  from  the  great  vessel  at  its  commence- 
ment,* and  continues  on  the  lower  flat  surface  of 


* It  often  opens  into  the  amide  by  a separate  orifice. 


GOO  Superior  Vena  Cava  and  its  Great  Branches . 

the  heart,  between  the  two  ventricles,  to  the  apex, 
accompanied  by  a branch  of  the  right  coronary  ar- 
tery. This  has  been  called  the  Middle  Vein  of  the 
heart. 

In  addition  to  these  there  are  several  veins  which 
begin  at  the  right  auricle,  and  extend  on  the  surface 
of  the  right  ventricle  towards  the  apex  of  the  heart. 
These  have  been  called  the  Anterior  Veins. 

SECTION  I. 

Of  the  SUPERIOR  or  DESCENDING  VENA  CAVA, 
and  the  Veins  ivhich  communicate  with  it. 

This  great  vessel  proceeds  upwards  from  the 
superior  and  posterior  part  of  the  right  sinus  or 
pouch  of  the  heart;*  and  a portion  of  it  is  so  involv- 
ed by  the  pericardium,  that  it  seems  to  be  included  in 
that  sac,  as  the  heart  is  in  this  situation.  It  is  some- 
what anterior  as  well  as  to  the  right  of  the  aorta.  It 
continues  above  the  pericardium,  adhering  to  the 
right  lamen  of  the  mediastinum,  and  rather  inclining 
forward.  When  it  is  as  high  as  the  lower  margin 
of  the  upper  rib,  it  sends  off  a very  large  branch, 
which  conveys  the  venous  blood  of  the  left  arm  and 
the  left  side  of  the  head  and  neck.  This  large  vein, 
which  is  very  important,  both  on  account  of  its  size 
and  its  situation,  proceeds  in  a transverse  direction 
within  the  sternum,  almost  in  contact  with  and  but 
little  below  the  upper  and  internal  margin  of  that 
bone.  Immediately  behind  or  within  the  origin  of 
the  left  sterno-mastoid  muscle,  it  divides  into  the 
left  subclavian,  which  preserves  a transverse  course, 
and  the  left  internal  jugular,  which  proceeds  to  the 
cavity  of  the  cranium  by  the  foramen  lacerum. 

After  sending  off"  this  transverse  branch  to  the  left, 


* See  (he  description  of  the.  heart.-  in  page  51.  of  this  volume. 


301 


Vena  Azygos . 

the  great  vein  continues  upwards  and  behind  the 
right  sterno-mastoid  muscle,  and  there  sends  off,  near- 
ly at  right  angles,  the  right  subclavian  vein.  After 
it  has  parted  with  this  vein,  it  takes  the  name  of  In- 
ternal Jugular,  and  continues  to  the  right  foramen 
lacerum,  in  the  basis  of  the  cranium.  The  superior 
vena  cava  is,  therefore,  principally  formed  by  the 
union  of  the  subciavians  and  internal  jugulars  from 
each  side  of  the  body. 

Immediately  after  the  superior  cava  rises  above 
the  pericardium,  before  it  divides  as  above  stated,  it 
sends  off,  from  its  posterior  part,  a large  vein  which 
is  single,  and  therefore  called 

VENA  AZYGOS. 

This  vessel  projects  backward  above  the  right 
pulmonary  artery  and  right  branch  of  the  trachea, 
and  then  curves  downwards  behind  them.  It  pro- 
ceeds down  the  spine  to  the  right  of  the  aorta  and  at 
a small  distance  from  it,  into  the  abdomen,  between 
the  crura  of  the  diaphragm,  and  sometimes  between 
some  of  the  portions  of  that  muscle,  which  are  at- 
tached to  the  dorsal  vertebrae.  In  the  abdomen  it 
often  anastomoses  either  with  the  lumbar  veins  or 
the  vena  cava. 

The  azygos  frequently  sends  off  several  small 
veins  from  its  curvature  to  the  contiguous  parts,  and 
also  the  right  Bronchial  Vein , which  passes  along 
the  ramifications  of  the  trachea  into  the  substance  of 
the  lungs.*  In  its  course  downwards  it  gives  off 
branches  to  the  oesophagus,  some  of  which  are  consi- 
derable. 

The  Inferior  Intercostal  Veins  originate  directly 
or  indirectly  from  the  azygos.  In  some  cases  there 
is  no  Superior  Intercostal  on  the  right  side ; and  then 


This  bronchial  vein  sometimes  arises  from  the  superior  cava. 


302  Inferior  intercostal  Veins , 

the  two  or  three  uppermost  of  the  right  intercostals, 
are  also  derived  from  the  azygos  ; and  often  origi- 
nate from  it  by  a common  trunk,  which  soon  divides. 
Most  commonly  the  ten  inferior  intercostals  on  the 
right  side  proceed  directly  from  the  azygos,  and  ac- 
company the  intercostal  arteries.  Their  posterior 
branches  pass  into  the  vertebral  cavity,  and  commu- 
nicate with  the  veins  which  are  there. 

About  the  sixth  or  seventh  rib,  the  vena  azygos 
frequently  sends  off  a branch  to  the  left  which  de- 
scends on  the  left  side  of  the  vertebrae,  and  sends  off 
those  Left  intercostal  veins  which  are  below  its  ori- 
gin. It  passes  through  the  diaphragm  with  the  aorta, 
or  to  the  left  of  it,  and  anastomoses  either  with  the 
azygos  itself,  or  in  a way  which  is  analogous  to  the 
anastomosis  of  that  vessel. 

The  Vena  Azygos  may  be  regarded  as  the  great 
trunk  of  the  veins  of  the  parietes  of  the  thorax, 
which  are  thus  collected,  because  they  could  not 
with  convenience  pass  singly  to  the  vena  cava,  as  the 
arteries  do  to  the  aorta. 

Soon  after  sending  off  the  vena  azygos,  the  Supe- 
rior Cava  sends  off  the  great  transverse  branch 
above  mentioned.  From  this  it  continues  upwards 
but  a short  distance,  when  it  divides,  behind  the 
right  sterno-mastoid  muscle,  into  the  right  subcla- 
vian and  right  internal  jugular. 

The  branches  of  the  superior  cava,  which  thus 
intervene  between  the  great  trunk  and  the  subdi- 
visions behind  the  sterno-mastoid  muscles,  are  often 
called  the  Subclavian  Veins  ; but  they  do  not  appear 
to  be  accurately  named.  For,  1st,  they  are  not  situ- 
ated under  the  clavicle,  and,  2dly,  they  are  the  com- 
mon trunks  of  the  subclavians  and  internal  jugulars 
united. 

There  is  a difference  in  the  places  where  some  of 
the  smaller  veins  originate  on  each  side.  The  inter- 


303 


Superior  Intercostal  Veins , 

iial  mammary  and  the  inferior  thyroid,  on  the  right 
side,  arise  from  the  superior  cava,  or  from  the  sub- 
clavian  at  its  origin.  On  the  left  side  they  arise  from 
the  subclavian. 

The  superior  intercostal  Veins 

Are  somewhat  different  on  the  two  sides.  That  on 
the  right  is  often  the  smallest  and  the  least  exten- 
sive. It  commonly  originates  from  the  posterior  and 
inferior  part  of  the  subclavian  opposite  to  the  origin 
of  the  vertebral,  and  is  generally  distributed  to  the 
first  and  second  intercostal  spaces,  but  rarely  to  the 
third. 

The  Left  Intercostal  frequently  originates  near  the 
left  internal  mammary,  and  sometimes  in  common 
with  it.  It  descends  behind  the  aorta,  on  the  left  of 
the  spine,  and  commonly  sends  off  the  six  upper  in- 
tercostal veins,  of  which  the  two  or  three  superior 
pass  upwards  from  a part  of  the  vein  which  is  oppo- 
site to  the  third  dorsal  vertebra.  Its  extent  is  very 
different  in  different  subjects.  In  some  instances  it 
passes  so  low  as  to  supply  the  seventh  or  eighth  in- 
tercostal space.  This  vein  also  gives  off  the  Left 
Bronchial  Vein,  which  sends  branches  to  the  oeso- 
phagus and  bronchial  glands. 

The  vertebral  Veins 

Arise  from  the  subclavians,  but  sometimes  they  pro=> 
ceed  differently  in  different  subjects  : the  right  pass- 
ing behind,  and  the  left  before,  the  subclavian  artery 
of  its  respective  side.  Each  of  them,  however,  be- 
comes contiguous  to  its  corresponding  artery.  When 
it  has  arrived  at  the  place  in  the  transverse  processes, 
where  the  artery  enters  the  vertebral  canal,  it  sends 
off  an  external  branch,  which  passes  up,  before  and 
nearly  in  contact  with,  those  processes,  and  gives 
ramifications  to  the  contiguous  muscles,  and  also  to 


304 


Vertebral  Veins. 


the  cavity  of  the  spine.  These  last  mentioned,  rami- 
fications enter  by  the  lateral  apertures  between  the 
transverse  processes,  and  anastomose  with  the  veins 
and  sinuses  of  the  cavity.  The  branch  often  finally 
terminates  in  the  lateral  sinus  of  the  dura  mater,  by 
passing  through  the  foramen  near  the  mastoid  process 
of  the  temporal  bone.  The  Main  Trunk  of  the  ver- 
tebral vein  generally  sends  off  another  external  branch 
to  the  muscles  near  the  basis  of  the  neck,  and  after- 
wards enters  the  canal  with  the  vertebral  artery. 
While  in  this  canal  it  generally  sends  off  two  branches 
through  each  of  the  lateral  apertures  between  the  ver- 
tebrae. One  of  these  branches  passes  backwards  to 
the  muscles  of  the  neck,  and  the  other  proceeds  into 
the  great  spinal  cavity,  and  communicates  with  the 
venous  sinuses. 

When  it  has  arrived  at  the  atlas,  the  Vertebral 
vein  sends  branches  to  the  contiguous  muscles  of  the 
neck.  It  also  frequently  sends  a branch  through  the 
posterior  condyloid  foramen  of  the  occipital  bone  to 
the  lateral  sinus. 

It  is  evident,  from  these  circumstances  that  the 
vertebral  vein  carries  a portion  of  blood  from  the 
sinuses  of  the  brain  and  of  the  spinal  marrow,  as 
well  as  from  the  muscles  of  the  neck,  into  the  sub- 
clavian veins. 

The  veins  of  the  head  are  frequently  very  differ- 
ent in  different  subjects. 

The  INTERNAL  JUGULAR , 

Already  mentioned,  is  often  almost  exclusively  ap- 
propriated to  the  cavity  of  the  cranium  ; and  all  the 
exterior  veins  of  the  head  are  ramifications  of  one  or 
more  smaller  vessels,  which  pass  up  superficially  on 
the  neck,  and  are  denominated  External  Jugulars . 
In  some  instances  almost  all  the  exterior  veins  of  the 
head  are  united  to  the  internal  jugular  at  the  upper 


The  internal  Jugular , 305 

part  of  the  neck,  and  it  of  course  conveys  the  blood 
of  the  exterior  as  well  as  of  the  interior  parts  of  the 
head.  Frequently  these  veins  are  divided  between 
the  internal  and  external  jugulars,  but  they  are  di- 
vided very  differently  in  different  subjects. 

The  Internal  Jugular,  however,  almost  always 
passes  in  the  same  direction  from  the  inside  of  the 
origin  of  the  sterno-mastoid  muscle  to  the  posterior 
foramen  lacerum  of  the  cranium.  It  is  deeply  seat- 
ed on  the  external  side  of  the  common  carotid  artery, 
and  under  the  sterno-mastoid  muscle.  Between  the 
upper  margin  of  the  thyroid  cartilage  and  the  angle 
of  the  lower  jaw,  it  often  sends  off  branches  which 
are  very  different  in  different  subjects,  but  commonly 
pass  to  the  anterior  parts  of  the  neck  and  face  : 
above  these  it  generally  sends  another  to  communi- 
cate with  the  external  jugular.  One  of  the  branches 
which  often  go  off  from  the  internal  jugular  is  that 
which  corresponds  with  the  superior  thyroid  or  la- 
ryngeal artery.  This  vein,  which  has  sometimes 
been  called  the  Guttural,  sends  many  ramifications 
to  the  thyroid  gland.  The  Ranular  veins,  which 
are  so  conspicuous  under  the  tongue,  are  also  derived 
from  it ; and  it  likewise  sends  branches  to  the  larynx 
and  pharynx. 

Before  the  internal  jugular  enters  the  foramen  la- 
cerum, it  suffers  a partial  dilatation,  which  is  gener- 
rally  larger  on  one  side  than  the  other. * This  dila- 
tation occupies  the  fossa  at  the  foramen  lacerum. 
After  passing  through  the  aforesaid  foramen,  the  in- 
ternal jugular  terminates  in  the  lateral  sinuses  of  the 

* When  the  veins  of  the  neck  are  injected,  it  very  often  appears  that  a 
considerable  portion  of  the  internal  jugular  is  much  larger  on  one  side  than 
the  other,  as  if  it  were  affected  with  varicose  distention. 

It  also  often  appears  that  the  general  arrangement  of  the  exterior  vein  is 
different  on  the  two  sides  of  the  head  and  neck, 

VOL,  II.  39 


306 


The  External  Jugular . 

dura  mater.*  These  and  the  other  sinuses  within 
the  cavity  of  the  cranium  are  important  portions  of 
the  venous  system,  which  are  interposed  between  the 
smaller  branches  spread  upon  the  pia  mater  and  the 
great  trunks  of  the  neck.  They  are  described  in 
the  account  of  the  brain,  (Yol.  I.  page  316.)  Into 
these  sinuses  the  very  numerous  veins  of  the  pia 
mater  open,  proceeding  to  the  sinuses  in  a direction 
the  reverse  of  that  in  which  the  blood  flows  in  those 
channels. 

These  veins  are  divided  very  minutely  on  the  pia 
mater  before  they  enter  the  substance  of  the  brain. 

Into  one  of  these  sinuses,  denominated  the  Ca- 
vernous, the  ophthalmic  vein  discharges  its  contents. 
This  vein  proceeds  from  the  anterior  part  of  the 
sinus  into  the  orbit  of  the  eye  through  the  sphenoid 
fissure. t Its  ramifications  correspond  generally  with 
those  of  the  ophthalmic  artery^  and  some  of  them 
pass  out  of  the  orbit  to  anastomose  with  the  branches 
of  the  facial  vein. 

The  superficial  veins  of  the  neck  are  variously 
arranged  in  different  persons.  There  is  often  one 
considerable  vein, 

The  EXTERNAL  JUGULAR, 

Which  is  sent  off  by  the  subclavian,  very  near  its 
union  with  the  internal  jugular ; but  sometimes  it 
goes  off  from  that  vein  much  nearer  the  shoulder. 
There  are  sometimes  two  external  jugulars,  an  ante- 

* It  is  asserted  that  the  internal  coat,  or  lining  membrane  of  the  inter, 
nal  jugulars,  is  continued  into  the  lateral  sinuses,  and  extends  throughout 
all  the  sinuses  of  the  dura  mater ; so  that  the  blood,  during  its  passage 
through  the  sinuses,  does  not  come  in  contact  with  any  membrane  different 
from  that  of  the  veins. 

f See  the  account  of  this  fissure  in  vol.  i.  p.  63. 

t The  Vasa  Vorticasa  of  the  choioides  aie  one  of  the  exceptions  to  this. 
See  vol.  i.  p-  356. 


General  Account  of  the  Great  Fein  of  the  Arm.  307 

rior  and  a posterior,  nearly  of  equal  size.  More  fre- 
quently one  of  them  is  much  smaller  than  the  other. 
In  a majority  of  cases,  the  principal  external  jugular 
goes  off  near  the  junction  of  the  internal  jugular  and 
subclavian,  as  above  stated,  and  proceeds  upwards 
towards  the  angle  of  the  lower  jaw,  passing  between 
the  platysma  myoides  and  the  stern o- mastoid  muscle. 
It  often  sends  off,  at  the  basis  of  the  neck,  one  or  more 
branches  to  the  contiguous  muscles,  and  then  proceeds 
upwards.  Near  the  angle  of  the  jaw,  it  often  com- 
municate&with  the  internal  jugular  : itthen  continues 
upwards,  covered  with  the  parotid  gland,  near  the 
temporal  artery,  and  finally  divides  into  superficial 
and  deep-seated  temporal  branches. 

The  External  Jugular,  near  the  angle  of  the  jaw, 
often  sends  off  the  facial  vein,  which  crosses  the  basis 
of  the  lower  jaw,  near  the  facial  artery,  and  distri- 
butes branches  to  the  side  of  the  face  and  to  the  fore- 
head. It  also  very  often  sends  off,  near  this  place, 
the  internal  maxillary  vein,  which  generally  ramifies 
in  such  a manner  that  its  branches  correspond  with 
those  of  the  internal  maxillary  artery.  Veins  which 
correspond  to  some  of  the  other  branches  of  the  exter- 
nal carotid  artery,  the  lingual,  occipital,  &c.  are  of- 
ten sent  off  near  this  place  by  the  external  jugular. 
They  take  the  names  of  the  arteries  to  which  they 
correspond,  and  commonly  accompany  them. 

The  SUBCLAVIAN  Vein, 

Although  it  originates  differently  on  the  two  sides  of 
the  neck,  is  situated  alike  on  each  of  them.  After 
parting  with  the  internal  jugular,  it  proceeds  over 
the  first  rib,  under  the  clavicle,  and  does  not  pass 
between  the  scaleni  muscles,  as  is  the  case  with  the 
arteries,  but  before  the  anterior  muscle.  It  soon 
joins  the  great  artery  of  the  arm,  and  proceeds  be- 
fore or  below  it  to  the  axilla.  In  this  situation  it  gives 


308  General  Account  of  the  Great  Vein  of  the  Arm. 

off  branches  to  the  contiguous  parts,  which  correspond 
with  those  given  off  by  the  artery.  In  this  course 
it  also  often  gives  off  a large  branch,  called  the 

CEPHALIC, 

Which  soon  becomes  superficial,  and  proceeds  down- 
wards between  the  margins  of  the  deltoid  and  pecto- 
ral muscles  : it  continues  superficial  on  the  external 
side  of  the  biceps  muscle,  sending  off  many  subcuta- 
neous branches.  Near  the  external  condyle  of  the  os 
humeri,  it  generally  sends  off  a branch  towards  the 
middle  of  the  anterior  part  of  the  fore-arm,  which  is 
called  the  Median  Cephalic,  and  also  some  other  su- 
perficial branches.  It  then  continues  over  the  radius, 
and  inclining  to  the  back  of  the  fore-arm,  until  it  ar- 
rives at  the  back  of  the  hand,  where  it  divides  into 
branches,  some  of  which  go  to  the  thumb. 

In  the  axilla,  the  great  vein,  there  called 

The  AXILLARY  Vein, 

Generally  divides  into  two  or  three  branches.  One, 
which  is  commonly  the  largest,  and  appears  like  the 
continuation  of  the  main  trunk,  is  called 

The  basilic  Vein . 

This  vessel  passes  down,  deeply  seated,  to  the  bend 
of  the  elbow.  It  becomes  superficial  near  the  inter- 
nal condyle,  and  divides  into  several  branches. — One 
of  these  generally  proceeds  to  join  the  median  branch 
of  the  cephalic,  and  from  the  union  of  the  two 
branches  is  formed  the  median  vein,  which  passes 
down  near  the  middle  of  the  anterior  part  of  the  fore- 
arm. This  vein  generally  sends  off  a branch  which 
proceeds  internally,  and  anastomoses  with  the  deep- 
seated  veins  of  the  fore- arm. 

There  are  frequently  two  other  branches  of  the 
basilic  vein.  One,  which  is  small,  passes  down  on 


Situation  of  the  Inferior  Vena  Cava.  309 

the  ulnar  side  of  the  anterior  part  of  the  fore-arm, 
but  does  not  extend  to  the  wrist.  The  other  passes 
down  on  the  ulna,  and  gradually  proceeds  to  the 
back  of  the  hand,  when  it  divides  into  several 
branches,  one  of  which  is  generally  appropriated  to 
the  little  finger. 

The  axillary  vein,  after  the  Basilic  leaves  it, 
sometimes  divides  into  two  branches,  and  sometimes 
continues  undivided.  In  either  case  it  accompanies 
the  humeral  artery,  and  takes  the  name  of  humeral 
Vein  or  Veins.  It  sends  off  branches  which  corres- 
pond to  those  of  the  artery,  and  continues  to  the  bend 
of  the  elbow  ; here  it  is  so  divided,  that  two  of  its 
ramifications  accompany  each  of  the  three  arteries  of 
the  fore-arm.  These  ramifications  sometimes  com- 
municate with  each  other  by  anastomosing  branches 
near  the  elbow,  and  they  communicate  also  with  the 
superficial  veins. 

The  superficial  veins  of  the  arm  are  so  different  in  dif- 
ferent subjects,  that  a general  description  will  rarely 
apply  accurately  to  an  individual  case.  It  may,  how- 
ever, be  observed,  that  a Cephalic  vein  will  generally 
be  found,  which  very  frequently  arises  from  the  sub- 
clavian instead  of  the  axillary,  and  commonly  conti- 
nues to  the  hand  on  the  radial  side  of  the  arm.  The 
superficial  veins,  on  the  ulnar  side  of  the  fore-arm, 
* very  frequently  are  branches  of  a large  vein  which  ac- 
companies the  humeral  artery  to  the  elbow,  viz.  the 
basilic  ; but  the  median  vein,  formed  by  branches  of 
the  cephalic  and  basilic  veins,  is  very  often  not  to  be 
found. 

SECTION  II. 

Of  the  INFERIOR  VENA  CAVA,  and  the  Veins 
which  are  connected  with  it. 

This  great  vessel  exceeds  the  Superior  Cava  in 
diameter.  It  proceeds  from  the  lower  part  of  the 


310  Situation  of  the  hiferior  Vena  Cava. 

right  auricle,  and  very  soon  perforates  the  dia- 
phragm, at  a small  distance  in  front  of  the  spine, 
and  rather  to  the  right  of  the  centre.  As  the  peri- 
cardium adheres  to  the  diaphragm  at  this  place,  the 
vessel  appears  to  leave  it  abruptly.  Immediately 
after  leaving  the  diaphragm,  it  proceeds  along  a 
groove  in  the  posterior  edge  of  the  liver,  formed  by 
the  great  lobe  and  the  lobulus  Spigelii.*  After 
leaving  the  liver,  it  continues  downwards,  inclining 
backward  and  to  the  left,  and  is  soon  in  contact  with 
the  aorta,  which  is  on  the  left  of  it.  It  accompanies 
the  aorta  to  its  great  bifurcation,  and  divides  in  the 
same  manner.  It  sends  off,  during  this  course, 
branches  to  the  Diaphragm,  Liver,  Right  Renal 
Gland,  the  Kidneys,  and  the  testicles ; and  also 
the  Lumbar  and  Middle  Sacral  veins. 

The  Inferior  Phrenic  Veins 

Are  thus  denominated  to  distinguish  them  from  other 
veins,  which  are  derived  from  the  internal  mammary, 
&c.  They  generally  accompany  the  phrenic  arteries, 
and  are  distributed  in  the  same  manner. 

The  hepatic  Veins 

Pass  off  from  the  vena  cava,  nearly  at  right  angles, 
into  the  substance  of  the  liver,  while  it  is  in  the 
groove  of  that  viscus,  and  before  it  has  proceeded 
more  than  eight  or  ten  lines  from  the  heart. 

They  arise  from  the  anterior  part  of  the  vena 
cava,  and  are  generally  three  in  number.  Some- 
times there  are  two  only,  but  then  one  of  them  di- 
vides immediately  after  it  enters  the  substance  of  the 
gland. 

The  distribution  of  these  vessels  in  the  liver  has 

4 Sometimes  it  is  completely  surrounded  by  the  live/. 


The  Vena  Portarum.**— Splenic  Vein.  311 

been  detailed  in  the  account  of  that  organ,  and  there- 
fore need  not  be  stated  here  ; but  the  veins  which 
unite  to  form  the  vena  portarum,  and  the  trunk  of 
that  great  vein  also,  before  it  is  connected  with  the 
liver,  may  be  regarded  as  a portion  of  the  regular 
venous  system,  and  ought  now  to  be  considered. 

The  VENA  PORTARUM 

Passes  downwards  from  the  great  sinus  of  the  liver 
behind  the  pancreas,  and  inclining  to  the  left.  In  this 
course  it  sends  branches  to  the  gall  bladder,  the  sto- 
mach and  pylorus,  and  the  duodenum.  At  the  up- 
per and  posterior  edge  of  the  pancreas,  it  sends  off 
a very  large  branch  to  the  spleen,  which  often  pass- 
es, with  slight  meanders,  along  a groove  in  the  pan- 
creas. 

The  SPLENIC  Vein 

Often  sends  off  the  inferior  mesenteric  vein, 
which  proceeds  downwards  between  the  aorta  and 
the  left  portion  of  the  colon.  It  also  sends  off  some 
of  the  coronary  veins  and  the  left  gastro  epiploic 
vein  to  the  stomach  ; many  small  branches  to  the  pan- 
creas; and,  finally,  either  from  the  main  trunk  or 
its  branches  before  they  enter  the  spleen,  the  venae 
breves,  which  pass  to  the  great  extremity  of  the  sto- 
mach. Before  it  enters  the  spleen,  it  forms  several 
ramifications,  which  accompany  the  branches  of  the 
splenic  artery. 

After  sending  off  the  splenic,  the  Vena  Portarum 
takes  the  name  of 

The  SUPERIOR  MESENTERIC  Vein; 

Which  is  larger  than  the  splenic,  and  passes  from 
behind  the  pancreas > before  the  transverse  portion  of 


312  Superior  Mesenteric  Vein.  —Emulgen t Veins, 

the  duodenum , into  the  mesentery ; where  it  accom- 
panies the  superior  mesenteric  artery. 

It  is  evident  that  the  above,  described  portion  of 
the  vena  portarum  simply  performs  the  functions  of 
a great  vein ; but  when  it  takes  on  the  arrangements 
for  entering  the  liver,  it  no  longer  acts  like  a vein, 
but  an  artery. 

The  lower  portion  of  the  trunk  of  this  vein  and  its 
ramifications  is  denominated  Vena  Portse  Ventralis. 
The  part  which  ramifies  in  the  liver,  Vena  Portx 
Hepatica. 

The  Capsular  Veins 

Are  small  vessels,  one  on  each  side.  That  on  the 
right  passes  from  the  vena  cava  to  the  right  glandula 
renalis.  That  on  the  left  arises  from  the  left  emul- 
gent  vein. 

The  EMULGENT,  or  RENAL  Veins, 

Are  very  large  vessels;  and,  like  the  arteries,  go  off 
nearly  at  right  angles,  one  to  each  kidney. 

The  right  emulgent  vein  is  not  so  long  as  the  left, 
and  it  is  rather  anterior  to  its  corresponding  artery. 
The  left  emulgent,  in  its  course  to  the  kidney,  cross- 
es  the  aorta,  and  is  anterior  to  it. 

These  veins  pass  to  the  sinus  of  each  kidney,  and 
ramify  before  they  enter  it.  The  ramifications  fol- 
lows those  of  the  arteries. 

The  Spermatic  Veins 

Arise  one  on  each  side : the  right  from  the  vena  cava 
and  the  left  from  the  emulgent  vein.  They  proceed 
downwards  behind  the  peritoneum,  and  on  the  psoas 
muscle  generally  divide  into  many  branches  which 
communicate  with  each  other  as  they  progress  down- 
wards, and  form  a plexus  denominated  Corpus 
Pampiniforme,  These  branches  proceed  in  the 


Internal  Iliac  and  its  Ramifications.  313 

spermatic  cord  to  the  back  of  the  testis.  The  prin- 
cipal part  enters  the  body  of  that  gland;  but  some  of 
the  branches  go  to  the  epididymis.  In  females  the 
spermatic  vein,  like  the  artery,  passes  to  the  ovary, 
the  uterus  and  its  appendages,  &c. 

The  Lumbar  Veins 

Correspond  to  the  arteries  of  the  same  name.  They 
arise  from  the  posterior  and  lateral  parts  of  the  in- 
ferior cava,  and  those  on  the  left  side  pass  under  the 
aorta. 

The  Middle  Sacral  Vein 

Resembles  the  artery  of  the  same  name  in  its  origin 
and  distribution. 

The  INFERIOR  VENA  CAVA  accompanies 
the  aorta  to  the  space  between  the  fourth  and  fifth 
lumbar  vertebrae,  and  there  it  also  divides  into  the 
two 

PRIMITIVE  ILIAC  VEINS. 

• 

The  left  vein  crosses  behind  the  artery  of  the  right 
side,  and  rather  behind  the  left  primitive  iliac  artery, 
which  it  accompanies  until  they  are  opposite  to  the 
junction  of  the  sacrum  and  ilium,  when  it  divides 
again,  like  the  artery,  into  the  internal  and  exter- 
nal iliac  veins. 

The  INTERNAL  ILIAC , or  HYPOGASTRIC 

Vein  ' 

Descends  into  the  pelvis  behind  the  artery,  which  i£ 
accompanies.  Its  ramifications  correspond  in  gene- 
ral with  those  of  the  artery,  and,  therefore,  need  not 
be  particularly  described. 

The  VENiE  VESICALES 

Have  such  peculiarities  that  their  ramifications  re- 
quire particular  attention.  They  arise  from  the  hy- 
Vol.  ii«  40 


314  JRamiJications  of  the  External  Iliac . 

pogastric,  very  near  the  origin  of  the  obturator,  and 
are  large  as  well  as  numerous. 

They  are  somewhat  different  in  the  two  sexes.  In 
men  they  form  a remarkable  plexus  on  the  lateral 
and  inferior  portions  of  the  bladder,  and  on  the  ve- 
siculse  seminales.  This  plexus  extends  more  or  less 
to  the  prostate : from  it  a number  of  veins  proceed  to 
the  symphisis  of  the  os  pubis,  which  communicate  in 
their  course  with  the  pudic  vein.  From  thence 
arises  the  great  vein  of  the  penis,  which  proceeds  in 
the  groove  between  the  corpora  cavernosa,  and  ter- 
minates in  the  glans  penis.  This  vein  often  divides, 
near  the  root  of  the  penis,  into  two : one  of  which  is 
in  the  groove,  and  the  other  more  superficial.* 

In  females,  the  venae  vesicales  form  a considerable 
plexus  on  each  side  of  the  bladder  and  vagina. — • 
Many  veins  pass  from  these  to  the  upper  portions 
of  the  bladder  and  the  contiguous  parts,  and  form 
plexuses.  The  clitoris  has  a dorsal  vein  like  the 
penis,  and  it  originates  in  a manner  analogous  to  the 
dorsal  vein  of  the  male. 

The  EXTERNAL  ILIAC  Vein . 

The  great  trunk  of  the  veins  of  the  lower  extremity 
proceeds  on  the  inside  of  the  artery,  under  the  crural 
arch  or  Poupart’s  ligament.  Before  it  passes  from 
under  the  arch,  it  sends  off  two  branches  which  an- 
swer to  the  circumflex  artery  of  the  ilium  and  to  the 
epigastric  artery. 

The  Circumflex  Vein 

Arises  from  the  external  side  of  the  iliac  vein,  and 
passes  towards  the  anterior  end  of  the  spine  of  the 

* The  pudic  veins  accompany  the  arteries  of  that  name.  They  com- 
wmnicate  with  the  plexus,  as  above  mentioned,  and  continue  into  the 
penis 


315 


Veins  of  the  Leg . 

ilium.  It  divides  into  branches  which  accompany 
those  of  the  artery  of  the  same  name. 

The  Epigastric  Vein 

Arises  from  the  external  iliac,  and  accompanies  the 
epigastric  artery.— After  passing  a small  distance  in=? 
ward  and  downward,  it  turns  up  on  the  inside  of  the 
abdominal  muscles.  In  the  first  part  of  its  course 
it  sends  off  some  small  branches  to  the  spermatic 
cord. 

After  passing  beyond  Poupart’s  ligament  the 
name  of  the  great  vessel  is  changed  from  external 
iliac  to 

FEMORAL  VEIN. 

It  proceeds  downwards  at  first  on  the  inside  of  the 
femoral  artery,  but  gradually  changes  its  relative 
situation,  so  that  in  the  thigh  and  in  the  ham  it  is 
behind  or  on  the  outside  of  that  vessel. 

At  a short  distance  below  Poupart’s  ligament,  af- 
ter giving  off  some  small  branches  to  the  external  or- 
gans  of  generation,  and  to  the  glands  of  the  groin,  it 
sends  off  on  the  internal  side  of  the  thigh  a very 
large  vein  which  is  called  the 

SAPHENA  MAJOR. 

This  vein  immediately  becomes  superficial,  and 
passes  down  on  the  internal  side  of  the  thigh,  some- 
what anteriorly;  giving  off  some  small  branches  to 
the  contiguous  parts,  soon  after  it  originates;  and 
many  superficial  veins  afterwards.  It  continues  along 
the  inside  of  the  knee  and  leg  to  the  internal  ankle, 
the  anterior  part  of  which  it  passes  over.  It  then 
proceeds  along  the  internal  part  of  the  upper  surface 
of  the  foot  to  the  middle,  when  it  curves  towards  the 
external  edge,  and  joins  the  lesser  saphena.  On  the 


GIG  Instances  of  peculiar  arrangement  of  the  Veins . 

leg  and  foot  it  also  sends  off  many  branches,  which 
anastomose  with  each  other,  and  with  those  of  the 
aforesaid  vein. 

The  femoral  vein,  after  parting  with  the  saphena, 
soon  sends  off  the  vena  profunda,  and  the  circum- 
flex® also,  when  they  do  not  arise  from  the  profun- 
da. These  veins  are  generally  larger  than  the  arte- 
ries to  which  they  correspond,  and  their  branches 
are  more  numerous ; but  they  observe  the  same 
course. 

The  great  vein  accompanies  the  artery  down  the 
thigh  and  through  the  perforation  in  the  biceps  ; 
but  it  changes  its  relative  position,  so  that  it  is 
placed  behind  or  on  the  exterior  side  of  the  artery 
at  the  lower  part  of  the  thigh.  It  is  very  often  be- 
hind it  in  the  ham,  where,  like  the  artery,  it  takes 
the  name  of  popliteal.  In  the  ham  it  sends  off  an- 
other superficial  vein,  which  seems  very  analogous 
to  the  basilar  vein  of  the  arm.  This  is  called 

The  Lesser  or  External  Saphena. 

It  proceeds  from  the  ham  over  the  external  head  of 
the  gastrocnemius,  and  down  the  outside  of  the  leg, 
sending  off  many  branches  in  its  course.  It  passes 
behind  the  external  ankle  and  near  the  exterior  edge 
of  the  upper  surface  of  the  foot,  about  the  middle  of 
which  it  inclines  towards  the  great  saphena,  and 
forms  with  it  the  anastomosis  already  mentioned. 

The  popliteal  vein,  after  passing  across  the  arti- 
culation, ramifies  like  the  artery,  but  sends  two 
veins,  which  accompany  each  of  the  three  arteries  of 
the  leg. 

In  a few  instances  some  of  the  larger  veins  have 
been  found  to  be  arranged  in  a manner  very  differ- 
ent from  that  which  is  commonly  observed. 


Pulmonary  Vessels,  317 

One  case  of  this  kind  has  already  been  mentioned 
in  the  account  of  the  liver,*  where  the  Vena  Porta- 
rum  terminated  in  the  Vena  Cava , below  the  liver, 
without  entering  into  it. 

Another  very  remarkable  instance  of  peculiar  ar- 
rangement is  to  be  seen  in  a preparation  now  in  the 
University  of  Pennsylvania,  in  which  the  Inferior 
Cava,  instead  of  opening  into  the  lower  part  of  the 
right  auricle,  passes  behind  it,  in  the  tract  of  the 
Vena  Azygos,  and  opens  into  the  Superior  Cava,  in 
the  place  where  the  Vena  Azygos  usually  communi- 
cates with  that  vessel,  receiving  the  Intercostal 
Veins  in  its  course. 

In  this  preparation,  the  HepaticVeins  communicate 
directly  with  the  right  auricle,  at  its  lower  part;  the 
middle  and  left  hepatic  veins  forming  one  trunk  before 
they  enter,  and  the  right  vein  passing  in  singly.f 

Of  the  PULMONARY  Arteries  and  Veins, 

Those  portions  of  the  Pulmonary  artery  and  veins 
which  are  distinct  from  the  lungs  may  be  described 
very  briefly. 

It  has  been  already  observed, % that  the  pulmonary 
artery  arises  from  the  left  and  most  anterior  part  of 
the  basis  of  the  right  ventricle,  and  proceeds  thence 

* See  note  to  p.  132,  of  this  volume, 

f The  foregoing  preparation  was  made  by  the  present  editor  in  1814, 
since  which  two  other  anomalous  cases  have  occurred  to  him. 

1819,  Case  1st.  The  ascending  cava  passed  into  the  thorax  on  the  left 
side  of  the  spine,  and  getting  as  far  as  its  upper  part,  was  joined  there  by 
the  trunk  of  the  internal  jugular  and  subclavian  of  the  left  side.  It  there 
passed  across  the  vessels  of  the  arch  of  the  aorta  and  joined  with  the  de» 
scending  cava.  The  vessels  of  th'e  liver  entered  the  heart  at  the  usual 
place,  in  the  lower  part  of  the  right  auricle. 

1820,  Case  2d.  The  trunk  formed  by  the  junction  of  the  internal  jugu- 
lar and  subclavian  of  the  left  side  instead  of  taking  its  usual  course,  passed 
down  vertically,  before  the  left  branch  of  the  pulmonary  artery  and  be 
fore  the  left  auricle,  then  making  a slight  curve  between  this  auricle  and 
the  diaphragm  joined  with  the  ascending  cava.-— Ed. 

t See  page  59  oi  this  volume 


3i  8 Pulmonary  Vessels. 

obliquely  backwards,  inclining  gradually  to  the  left 
side  for  about  eighteen  or  twenty  lines  when  it  divides 
into  two  branches,  which  pass  to  the  two  lungs.  This 
course  places  it  under  the  curve  of  the  aorta  : for  that 
great  vessel  passes  over  the  right  branch  of  the  pul- 
monary artery,  and  the  right  side  of  the  main  trunk 
of  it,  in  such  a manner  that  it  proceeds  downwards 
between  the  two  branches  and  behind  the  angle  form- 
ed by  their  bifurcation.  From  this  place  of  bifurcation 
a short  ligament  proceeds  to  the  lower  part  of  the  curve 
of  the  aorta,  which  is  almost  in  contact  with  it.  This 
ligament  was  originally  the  canal  that  formed  the 
communication  between  the  pulmonary  artery  and 
the  aorta  of  the  foetus.  Each  of  the  great  branches 
of  the  pulmonary  artery  takes  a direction  backwards, 
and  to  its  respective  side.  It  soon  joins  the  corres- 
ponding branch  of  the  trachea  and  the  two  pulmona- 
ry veins,  being  anterior  to  the  branch  of  the  trachea, 
and  above  the  pulmonary  veins.  It  is  also  invested, 
in  common  with  them,  by  that  portion  of  the  pleura 
which  forms  the  mediastinum,  and  thus  enters  into 
the  composition  of  the  root  of  the  lungs. 

The  Pulmonary  Veins  are  four  in  number — two 
on  each  side.  In  conformity  to  the  mode  of  descrip- 
tion which  we  have  adopted,  it  may  be  said  that  they 
arise  from  the  sides  of  the  Left  Auricle , and  proceed 
nearly  in  a transverse  direction,  two  of  them  to  each 
lung ; where  they  accompany  the  branches  of  the 
artery  and  of  the  trachea,  being  invested  by  the 
mediastinum  in  common  with  these  branches.  It 
has  been  observed,  that  they  differ  from  veins  in 
general,  by  preserving  a diameter  nearly  similar  to 
that  of  the  arteries  which  they  accompany. 


SYSTEM  OF  ANATOMY. 

PART  X. 


OF  THE  NERVES. 

The  nerves  are  those  whitish  cords  which  pass 
from  the  brain  and  spinal  marrow  to  the  various  parts 
of  the  body. 

A general  account  of  their  origin  is  contained  in 
the  description  of  the  basis  of  the  brain  and  of  the 
spinal  marrow,*  which  may  be  considered  as  intro- 
ductory to  the  present  subject. 

The  nerves,  in  general,  appear  to  be  bundles  or 
fasciculi  of  small  cords,  each  of  which  is  composed 
of  a series  of  fibres  that  are  still  smaller.  These 
fibres  consist  of  medullary  matter,  which  is  derived 
from  the  brain  and  spinal  marrow,  and  is  enclosed  in 
a membranous  sheath  that  appears  to  arise  from  the 
pia  mater.  The  smaller  the  fibre  the  more  delicate 
is  the  membrane  which  invests  it. 

As  the  nerves  proceed  from  the  brain  and  spinal 
marrow,  through  the  foramina  of  the  cranium  and  the 
spine,  they  are  enclosed  in  a sheath  formed  by  the 
dura  mater;  but  when  they  arrive  at  the  exterior 
extremities  of  the  foramina  in  those  bones,  this  coat, 
derived  from  the  dura  mater,  appears  to  separate 
into  two  lamina.  The  exterior  lamen  combines 
with  the  periosteum,  and  the  interior  continues  to  in- 


* See  volume  I.  p^ge  33? 


320  General  Structure  of  the  Nerve. 

vest  the  nerve,  but  seems  to  change  immediately  into 
cellular  substance  ; so  that  the  exterior  coat  of  the 
nerves  may  be  regarded  as  composed  of  cellular 
membrane,  which  is  continued  from  the  sheath  de- 
rived from  the  dura  mater. 

It  has  been  supposed  that  the  membrane  which 
forms  the  sheaths  for  the  medullary  fibrils,  of  which 
the  nerves  are  composed,  is  of  a peculiar  nature ; 
but  it  appears  to  be  derived  from  the  pia  mater,  in- 
vesting the  brain  and  the  spinal  marrow.  It  is  very 
vascular.* 

The  ramification  of  a nerve  is  simply  the  separa- 
tion of  some  fibres  from  the  general  fasciculus.  The 
branch  commonly  forms  an  acute  angle  with  the  main 
trunk. 

The  course  of  these  branches  from  their  origin  to 
their  termination,  is  generally  as  straight  as  possible. 

When  the  nervous  cords  are  examined  in  an  ani- 
mal recently  dead,  there  is  an  appearance  of  white 
lines  arranged  in  a transverse  or  spiral  direction. 
The  cause  of  this  appearance  is  not  well  understood. 

In  various  parts  of  the  body  net  works  are  formed 
by  the  combination  of  different  nerves,  or  the  branches 
of  nerves.  In  those  instances  the  branches  of  one 
nerve,  unite  with  those  of  another,  and  form  new 
branches.  These  new  branches  again  divide,  and 
their  ramifications  unite  with  other  new  ramifications 
to  form  other  new  trunks.  These  new  trunks  divide 
again,  and  form  new  combinations  in  the  same  way. 

The  trunks  last  formed  proceed  to  the  different 

* Several  authors  have  written  professedly  on  the  structure  of  the 
nerves,  viz.  Monro,  in  his  “ Observations  on  the  Structure  and  Functions 
of  the  nervous  System.” — Bichat,  “ Anatomie  Generale.” — Fontana, 
“ Treatise  on  the  Poison  of  the  Viper.” — Reil,  “ Exercitationes  Anato- 
mies.”— Scarpa,  “ Annotations  Academicse.” — Prochaska,  “ De  Struc- 
tura  Nervorum.” 

I regret,  that  it  has  not  been  in  my  power  to  procure  Reil,  Prcchask:!, 
or  Scarpa. 


321 


Plexuses . — - Ganglions. 

parts  of  the  body,  as  other  nerves  do  which  arise  im- 
mediately from  the  brain. 

These  combinations  are  denominated  Plexuses. 
There  are  several  of  them  in  the  cavities  of  the  abdo- 
men and  thorax,  formed  by  the  ramifications  of  the 
par  vagum  and  the  sympathetic  nerves.  The  four 
lower  cervical  and  the  first  dorsal  nerve  form  a very 
remarkable  plexus  of  this  kind,  which  extends  from 
the  side  of  the  neck  to  the  axilla,  and  forms  the 
nerves  of  the  arm.  The  lumbar  nerves  form  a similar 
plexus,  although  not  so  complex,  from  which  the  cru- 
ral nerve  arises.  The  anterior  nerves  of  the  sacrum 
also  unite  for  the  formation  of  the  great  sciatic  nerve. 

It  appears  to  be  clearly  ascertained,  that  the  great 
object  of  this  peculiar  arrangement  is  the  combina- 
tion of  nervous  fibres  from  many  different  sources, 
in  each  of  the  nerves,  which  are  distributed  to  any 
organ.  Thus,  the  smaller  nerves  of  the  arm  that  are 
distributed  to  the  different  parts,  are  not  to  be  re- 
garded simply  as  branches  of  any  one  of  the  five 
nerves  which  are  appropriated  to  the  upper  extre- 
mity, but  as  composed  of  fibres  which  are  derived 
from  each  of  them. 

Many  of  the  nerves  are  enlarged  in  particular 
places  so  as  to  form  small  circumscribed  tumours, 
which  are  denominated  Ganglions. 

These  Ganglions  are  generally  of  a reddish  co- 
lour. By  very  dextrous  management,  they  can  be 
shown  to  consist  of  a texture  of  fibres.  The  larger 
cords,  which  compose  the  nerve,  seem  suddenly  to 
be  resolved  into  the  small  fibres,  of  which  they  con- 
sist. These  small  fibres,  after  proceeding  separate- 
ly a greater  or  lesser  distance,  according  to  the  size 
of  the  ganglion,  and  changing  their  relative  situa- 
tion, are  again  combined  in  cords  whieh  recompose 
the  nerve. 

These  fibres  appear  to  be  surrounded  by  a fine 

Vol,  ii.  41 


322  Structure  of  Ganglions. 

cellular  substance,  which  is  vascular,  moist  and  soft. 
It  is  asserted  that,  in  fat  subjects,  an  oily  substance, 
resembling  fat ; and  in  hydropic  subjects,  a serous 
fluid  has  been  found  in  this  texture. 

Ganglions  are  often  connected  with  but  one  nerve, 
which  seems  to  enter  at  one  extremity  and  go  out  at 
the  other.  But  they  frequently  receive  additional 
branches  from  other  nerves,  and  send  off  additional 
branches  to  parts  different  from  those  to  which  their 
principal  nerves  are  directed.  When  connected  with 
but  one  nerve,  they  have  been  called  simple  gang- 
lions: when  they  receive  and  give  off  additional 
branches,  they  are  denominated  compound  gang- 
lions.— It  does  not  appear  that  there  is  any  impor- 
tant  difference  in  their  structure  in  these  cases. 

The  simple  ganglions  occur  in  the  nerves  of  the 
spinal  marrow— the  posterior  fasciculus  of  the  nerves 
having  always  formed  a ganglion  before  it  is  joined 
by  the  anterior  fasciculus.  The  sympathetic  nerve, 
throughout  its  whole  extent,  forms  compound  gang- 
lions. 

The  use  of  this  particular  structure  does  not  ap- 
pear to  be  perfectly  known.  It  seems,  however, 
certain,  that  the  different  fibres— (of  which  the 
nerves  forming  ganglions  are  composed)— are  blend- 
ed together  and  arranged  in  a manner  different  from 
that  in  which  they  were  arranged  before  the  nerve 
entered  the  ganglion. 

It  ought  to  be  observed,  that  the  combination  of 
nervous  fibrillse,  so  as  to  bring  together  those  fibrils 
which  originally  belonged  to  different  cords,  seems 
to  have  been  kept  in  view  throughout  the  whole  ar- 
rangement of  the  nervous  system.  It  is  not  only  in 
the  plexus  and  the  ganglion  that  this  appears,  but 
also  in  some  of  the  larger  nerves  ; for  in  them,  the 
fibres  which  form  the  cords  that  compose  the  nerve, 
instead  of  running  parallel  to  each  other,  along  the 


Reproduction  of  Nerves.  323 

whole  extent  of  the  nerve,  form  a species  of  plexus  in 
their  course ; separating  from  the  fibres  with  which 
they  were  originally  combined,  and  uniting  with  the 
fibres  of  other  cords  ; as  in  other  cases  of  plexus.* 

There  have  been  doubts  respecting  the  possibility 
of  a reproduction  of  the  substance  of  the  nerves  when 
it  has  been  destroyed ; but  it  appears  to  have  been 
clearly  proved  by  the  experiments  of  Mr.  Haighton, 
that  a reproduction  does  really  take  place.f 

Nine  pair  of  nerves  proceed  from  the  brain  through 
the  foramina  of  the  cranium.  They  are  called  Nerves 
of  the  Brain , or  Cerebral  Nerves.  One  pair  passes 
off  between  the  cranium  and  the  spine,  which  is  call- 
ed Sub-Occipital.  Twenty-nine  or  thirty  pair  pass 
through  the  foramina  of  the  spine  : they  are  deno- 
minated Cervical,  Dorsal,  Lumbar , and  Sacral , 
from  the  bones  with  which  they  are  respectively 
connected.  There  are  seven  pair  of  Cervical  nerves, 
twelve  Dorsal,  five  Lumbar,  and  five  or  six  Sacral — - 
amounting,  with  the  nerves  of  the  brain,  to  thirty- 
nine  or  forty  pair. 

NERVES  OF  THE  BRAIN 

The  nerves  which  go  off  from  the  brain  and  me- 
dulla oblongata  are  named  numerically,  according 
to  the  order  in  which  they  occur ; beginning  with 
the  anterior.  They  also  have  other  names,  which 
generally  are  expressive  of  the  functions  of  the  dif- 
ferent parts  to  which  they  are  distributed. 

Those  which  go  to  the  nose  are  anterior  to  all  the 
others,  and  are  therefore  denominated 

THE  FIRST  FAIR,  OR  THE  OLFACTORY  NERVES. 

They  arise  by  three  delicate  white  fibres  from  the 

* See  Monro’s  Observations  on  the  Structure  and  Functions  of  the  Ner- 
vous System.  Plate  xviii. 

t See  London  Philosophical  Transactions,  for  1795,  Part  I. 


324  Olfactory  Nerves . 

under  and  posterior  part  of  the  anterior  lobes  of  the 
brain,  being  derived  from  the  Corpora  Striata.  They 
proceed  forward  to  the  depression  on  the  cribriform 
plate  of  the  ethmoid  bone,  on  each  side  of  the  crista 
galli.  The  upper  surface  occupies  a small  sulcus 
formed  by  the  convolutions  of  the  lower  surface  of 
the  brain,  and,  therefore,  has  a longitudinal  ridge  on 
it.  The  lower  surface  is  flat.  Their  texture  is  like 
that  of  the  medullary  part  of  the  brain. 

On  each  side  of  the  crista  galli  each  of  them  forms 
a pulpy  enlargement  of  a brownish  colour,  which  is 
called  the  bulb , and  has  been  considered  as  a gang- 
lion. 

From  this  bulb  many  fine  and  delicate  cords  go  off, 
which  proceed  through  the  dura  mater  and  the  fora= 
mina  of  the  cribriform  plate  to  the  Schneiderian 
membrane. — These  ramifications  of  the  olfactory 
nerve  seem  to  receive  a coat  from  the  dura  mater, 
as  they  are  much  more  firm  after  they  have  passed 
through  it.  They  appear  to  be  arranged  in  two  rows 
as  they  proceed  from  the  ethmoid  bone — one  running 
near  to  the  septum,  and  the  other  to  the  opposite 
surface  of  the  ethmoid  bone."*' 

THE  SECOND  PAIR,  OR  THE  OPTIC  NERNES, 

Originate  from  the  Thalami  Nervorum  Opticorum , 
and  appear  on  the  external  and  lower  surface  of  the 
brain,  on  each  side  of  the  sella  turcica. 

Each  of  them  seems  like  a cord  of  medullary  mat- 
ter, enclosed  in  a coat  derived  from  the  pia  mater,  and 
has  not  the  fasciculated  appearance  of  the  other  nerves. 
The  medullary  matter,  however,  appears  to  be  divided 
by  processes  that  pass  through  it,  which  are  derived 
from  the  coat  of  the  nerve. 


See  VoJ-  n.  p a. 


325 


Second  and  Third  Pair  of  JYerves, 

They  proceed  obliquely  forward,  and  inward,  on 
each  side  of  the  sella  turcica,  in  contact  with  the 
brownish  cineritious  substance,  in  which  the  infundi- 
bulum and  the  corpora  albican tia  of  Willis  are  situa- 
ted.* Anterior  to  this  substance  they  come  in  con- 
tact with  each  other,  and  again  separate,  in  such  a 
way,  that  it  is  an  undecided  question  whether  they 
decussate  each  other,  or  whether  each  forms  an  an- 
gle, and  is  in  contact  with  the  other  at  the  angle. 

From  this  place  of  contact,  each  nerve  proceeds 
to  its  respective  foramen  opticum,  where  it  receives 
a coat  from  the  dura  mater,  which  extends  with  it  to 
the  eye,  as  has  been  described  in  the  account  of  that 
organ. 

THE  THIRD  PAIR  OF  NERVES 

Are  sometimes  called  Motor es  Oculorum , in  conse- 
quence of  their  distribution  to  several  muscles  of  the 
eye.  They  arise  at  the  inside  of  the  crura  cerebri, 
and  make  their  appearance  on  the  basis  of  the  brain^ 
at  the  anterior  part  of  the  pons  Varolii. 

They  originate  by  numerous  threads,  which  soon 
unite  so  as  to  form  a cord,  which  passes  through  the 
dura  mater,  on  each  side  of  the  posterior  clinoid  pro- 
cess, and  continues  through  the  cavernous  sinus,  and 
the  foramen  lacerum,  to  the  orbit  of  the  eye. 

Before  this  nerve  enters  the  orbit  it  generally  di- 
vides into  two  branches,  which  are  situated  one  above 
the  other.  The  Uppermost  Branch  is  spent  princi- 
pally upon  the  rectus  superior  muscle  of  the  eye,  but 
sends  a twig  to  the  levator  palpebrae.  The  Inferior 
Branch  is  distributed  to  two  of  the  recti  muscles, 
viz.  the  internus  and  the  inferior,  and  also  to  the 
inferior  oblique.  It  likewise  sends  a twig  to  a small 
ganglion  in  the  orbit,  called  the  Lenticular  or  Oph - 


* See  VoL  I.  page  323 


^526  Fourth  and  Fifth  Fair  of  Nerves. 

thalmic  Ganglion,*  from  which  proceed  the  fine 
nervous  fibres  that  perforate  the  sclerotica  coat.f 

THE  FOURTH  FAIR  OF  NERVES 

Are  called  the  Pathetic,  in  consequence  of  the  ex- 
pression  of  the  countenance  produced  by  the  action 
of  the  muscle  on  which  they  are  spent.  They  arise 
from  the  side  of  the  valve  of  the  brain,  below  and  be- 
hind the  Tubercula  Quadrigeminal  and  are  so  small 
that  they  appear  like  sewing  thread.  They  proceed 
round  the  crura  of  the  cerebrum,  and  appear  on  the 
surface  between  the  pons  Varolii  arid  the  middle 
lobes  of  the  brain.  They  proceed  along  the  edge  of 
the  tentorium  which  they  perforate,  and  passing 
through  the  upper  part  of  the  cavernous  sinus,  enter 
the  orbit  by  the  foramina  lacera.  They  are  exclu- 
sively appropriated  to  the  Superior  Oblique  or  Troch- 
learis  muscle. 

THE  FIFTH  PAIR  OF  NERVES 

Are  called  Trigemina,  because  each  nerve  divides 
into  three  great  branches. 

These  nerves  arise  from  the  crura  of  the  cerebel- 
lum where  they  unite  to  the  pons  Varolii,  by  distinct 
fibres,  which  are  connected  so  as  to  form  a cord  or 
nerve,  that  is  larger  than  any  other  nerve  of  the 
brain.  In  many  subjects  this  cord  seems  partially 
divided  into  two  portions,  the  anterior  of  which  is 
much  smaller  than  the  posterior,  and  appears  softer 
at  its  origin. 

It  passes  into  a short  canal  formed  by  the  dura 
mater,  near  the  anterior  extremity  of  the  petrous  por- 

* This  ganglion,  which  is  considered  as  the  smallest  in  the  body  lies  on 
the  outside  of  the  optic  nerve,  near  its  entrance  into  the  orbit,  and  is  ge- 
nerally surrounded  by  soft  adipose  matter, 
t See  Vol  I.  page  356. 


S2  7 


First  Branch  of  the  Fifth  Fair . 

Sion  of  the  temporal  bone,  at  a small  distance  below 
the  edge  of  the  tentorium.  It  is  perfectly  loose  and 
free  from  adhesion  to  the  surface  of  this  canal ; but 
it  soon  passes  out  of  it  under  the  dura  mater,  and  then 
adheres  to  that  membrane.  After  leaving  the  canal 
it  expands  like  a fan,  but  still  consists  of  fine  fibres 
which  have  some  firmness.  It  is  said  that  there  are 
seventy  or  eighty  of  these  fibres  in  the  expansion,  but 
they  appear  to  be  more  numerous.  Round  the  cir- 
cumference of  the  expansion  is  a substance  of  a brown- 
ish colour,  into  which  the  fibres  enter.  This  is  the 
Semilunar  Ganglion,  or  the  Ganglion  of  Gasser , 
and  from  it  the  three  nerves  go  off. 

These  nerves  pass  off  from  the  convex  side  of  the 
Ganglion,  and  are  denominated  the  Ophthalmic,  the 
Superior  Maxillary,  and  the  Inferior  Maxillary. 

The  Ophthalmic  Nerve 

Passes  into  the  orbit  of  the  eye  through  the  foramen 
lacerum : it  there  divides  into  several  branches,  which 
are  called,  from  their  distribution,  the  Frontal  or  Su- 
pra Orbitar,  the  Nasal,  and  the  Lachrymal. 

The  Frontal  or  Supra  Orbitar  branch  proceeds 
forward  in  the  upper  part  of  the  orbit,  exterior  to 
the  membrane  which  lines  it,  and  divides  into  two 
ramifications.  One  of  these  is  small,  and  passes  out 
of  the  orbit  near  the  pulley  of  the  superior  oblique, 
to  be  spent  upon  the  orbicularis  muscle  and  the  con- 
tiguous parts. 

The  other  ramification  passes  through  the  Supra 
Orbitary  Foramen,  or  through  the  notch,  which  is  in 
the  place  of  that  foramen,  and  divides  into  a number 
of  twigs,  some  of  which  pass  transversely  towards 
the  side  of  the  head,  and  communicate  with  twigs 
from  the  portio  dura.  Most  of  the  others  extend  up- 
wards on  the  head.  Some  are  distributed  to  the  an- 


328  Second  Branch  of  the  Fifth  Pair. 

terior  part  of  the  oceipito-frontalis  muscle,  and  the 
integuments  of  the  forehead ; others  are  spent  upon 
the  upper  portion  of  the  scalp.  Some  of  the  extreme 
parts  of  these  ramifications  also  communicate  with  the 
portio  dura. 

The  Nasal  Branch  proceeds  obliquely  forward 
towards  the  inner  side  of  the  orbit,  and  sends  a twig 
in  its  course  to  the  lenticular  ganglion.  It  also  sends 
off  some  small  twigs,  to  join  the  ciliary  nerves  which 
go  from  the  ganglion.  On  the  inside  of  the  orbit  a 
branch  leaves  it,  which  proceeds  through  the  Fora- 
men Orhitare  Internum  Anterius  to  the  cavity  of 
the  cranium,  and  passes  a small  distance  upon  the 
cribriform  plate  of  the  ethmoid  bone,  under  the  dura 
mater,  to  a fissure  in  the  said  plate  near  the  crista 
galli,  through  which  it  proceeds  into  the  cavity  of 
the  nose.  Here  it  divides  into  twigs,  some  of  which 
pass  on  the  septum  near  its  anterior  edge,  and  ter- 
minate  on  the  integuments  at  the  end  of  the  nose, 
while  others  pass  down  on  the  inferior  turbinated 
bone. 

After  parting  with  the  ramification  to  the  nose,  the 
remainder  of  the  nasal  branch  continues  to  the  in- 
ternal canthus  of  the  eye,  and  sends  twigs  to  the 
lachrymal  sac,  the  caruncula  lachrymalis,  the  eye- 
lids, and  the  exterior  surface  of  the  upper  part  of  the 
nose. 

The  Lachrymal  Branch  proceeds  obliquely  for- 
ward and  outwards,  towards  the  lachrymal  gland. 
In  its  course  it  sends  off  a twig  which  passes  through 
the  spheno  maxillary  fissure,  and  communicates  with 
a twig  of  the  upper  maxillary  nerve,  and  one  or 
more  twigs  that  pass  to  foramina  in  the  malar  bone. 
The  main  branch  passes  to  the  lachrymal  gland,  and 
some  twigs  continue  beyond  it  to  the  contiguous 
parts. 


829 


Second  Branch  of  the  Fifth  Pair. 

The  Superior  Maxillary  Nerve. 

The  second  branch  of  the  fifth  pair  is  examined 
with  great  difficulty  on  account  of  its  peculiar  situa- 
tion. It  proceeds  from  the  semilunar  ganglion,  and 
passes  through  the  foramen  rotundum  of  the  sphe- 
noid bone  into  the  upper  part  of  the  zygomatic  fossa. 
In  this  situation  it  sends  a twig  to  the  orbit  by  the 
spheno  maxillary  fissure,  and  a branch,  called  the 
Infra  Orbitar,  which  appears  like  the  main  nerve, 
as  it  preserves  a similar  direction,  to  the  infra  orbitar 
eanal.  At  the  same  place  it  sends  downwards  two 
branches  which*  unite  together  almost  immediately  af- 
ter their  origin,  and,  as  soon  as  they  have  united,  en- 
large into  a ganglion.*  This  ganglion  is  called  the 
Spheno- Palatine.  It  is  rather  of  a triangular  figure, 
and  lies  very  near  the  spheno-palatine  foramen.  It 
gives  off  a posterior  braneh,  which  passes  through  the 
pterygoid  foramen  to  the  cavity  of  the  cranium : some 
branches  which  proceed  through  the  spheno-palatine 
foramen  to  the  nose,  and  are  called  the  Spheno- Pala- 
tine or  Lateral  JYasal Nerves:  and  an  inferior  branch 
that  proceeds  through  the  posterior  palatine  canal, 
and  is  called  the  Palatine  Nerve. 

The  small  braneh,  which  was  first  mentioned,  as 
going  to  the  orbit  by  the  spheno  maxillary  fissure, 
divides  into  two  ramifications.  One  of  them  unites 
with  a twig  of  the  lachrymal  branch  above  mention- 
ed, and  passes  out  of  the  orbit,  through  a foramen  in 
the  malar  bone,  to  the  face ; where  it  is  distributed. 
The  other  passes  also  through  a foramen  of  the  ma- 
lar bone,  into  the  temporal  fossa,  and,  after  uniting 
with  twigs  from  the  Inferior  Maxillary  Nerve , pro- 
ceeds backwards  and  perforates  the  aponeurosis  of 

* Sometimes  a single  branch  passes  downwards  instead  of  two  ; but  it 
forms  a ganglion  in  the  same  place. 

Vol.  n.  42 


330 


Superior  Maxillary  Nerve. 

the  temporal  muscle,  to  terminate  on  the  integuments 
of  the  temporal  region. 

Before  the  Infra  Orbitar  branch  enters  the  canal 
of  that  name,  it  sends  off  two  twigs,  called  Posteriw 
Dental  Nerves , which  pass  downwards  on  the  tube- 
rosity of  the  upper  maxillary  bone,  and  enter  into 
small  canals  in  that  bone,  that  are  situated  behind 
the  Antrum  Maxillare.  They  subdivide  into  fine 
twigs  that  proceed  forward  to  the  alveoli  of  three  or 
four  of  the  last  molar  teeth ; and  penetrate  each  of 
the  roots  by  a cavity  at  its  extremity.  Twigs  also 
proceed  from  thege  nerves  to  the  posterior  part  of  the 
gums  and  buccinator  muscle. 

After  the  posterior  dental  nerves  have  left  it,  the 
Infra  Orbitar  nerve  proceeds  forwards  in  the  canal  of 
that  name ; and  near  the  extremity  of  it,  gives  off  the 
anterior  dental  nerve,  which  accompanies  it  for  some 
distance,  and  then  proceeds  downwards  in  a canal  in 
the  bone  anterior  to  the  antrum  maxillare.  In  its 
course  this  nerve  divides  into  many  fibres,  which  pass 
to  the  roots  of  the  incisor,  canine,  and  small  molar 
teeth,  each  in  its  proper  eanal.  These  dental  branches 
sometimes  pass  in  the  antrum  maxillare  between  the 
lining  membrane  and  the  bones.  The  Infra  Orbitar 
nerve  passes  out  of  the  foramen  upon  the  cheek,  and 
divides  into  several  branches  of  considerable  size, 
which  are  distributed  on  the  face  from  the  side  of  the 
nose  to  the  back  of  the  cheek,  and  also  upon  the  un- 
der eye-lid  and  the  upper  lip. 

The  Pterygoid  Nerve , or  posterior  branch,  passes 
backwards,  from  the  ganglion  to  a eanal  in  the  base 
of  the  pterygoid  process  of  the  Os  Sphenoides,  and 
proceeds  through  it.  After  leaving  this  canal,  it 
passes  through  a substance  almost  as  firm  as  carti- 
lage, which  closes  the  anterior  foramen  lacerum,  at 
the  basis  of  the  cranium;  and  divides  into  two 
branchy  The  smallest  of  them,  called  the  Vidian 


Superior  Moccdlldry  Nerve , 331 

Nerve , proceeds  with  a small  artery  to  the  small  fo- 
ramen, or  Hiatus  Fallopii,  on  the  anterior  side  of  the 
petrous  portion  of  the  temporal  bone,  and  continues, 
through  a small  canal,  to  join  the  Portio  Dura  of  the 
seventh  pair  in  the  larger  canal,  called  the  Aqueduct 
of  Fallopius , at  the  first  tarn  in  that  canal.*  The 
other  branch  of  the  pterygoid  nerve  proceeds  to  the 
Foramen  Carotieum,  and  passes  through  it,  with  a 
twig  of  the  sixth  pair,  to  join  the  first  cervical  gan- 
glion of  the  Intercostal  Nerve. 

The  Spheno- Palatine,  or  Lateral  Nasal  Nerves, 
consist  of  several  branches  which  pass  from  the 
spheno-palatine  ganglion  through  the  Spheno-pala- 
tine  foramen  into  the  nose.  Some  of  them  are  dis- 
tributed to  that  part  of  the  pituitary  membrane,  which 
is  above  the  upper  meatus,  and  others  to  the  part  which 
is  immediately  below  it.  Some  of  the  branches  which 
thus  enter  th£  nose  are  spread  upon  the  septum ; one 
among  them  extends  upon  it,  downwards  and  for- 
wards to  the  anterior  part  of  the  palatine  process  of 
the  upper  maxillary  bone,  where  it  enters  into  the 
foramen  incisivum,  and  terminates  in  a papilla  in  the 
roof  of  the  month. f 

The  Palatine  Branch  proceeds  through  the  canal 
formed  by  the  upper  maxillary  and  palate  bones,  to 
the  roof  of  the  mouth  and  the  soft  palate.  Soon  af- 
ter its  origin,  it  sends  off  a twig  which  proceeds 
down  a small  canal  that  is  behind  it.  It  also  sends 
off,  as  it  proceeds  downwards,  several  twigs  to  that 
part  of  the  membrane  of  the  nose  which  covers  the 

* The  late  Mr.  John  Hunter  believed  that  this  nerve  parts  from  the 
portio  dura  at  the  lower  end  of  the  aqueduct,  and  is  the  chorda  tym= 
pani. 

f The  curious  distribution  of  this  nerve  appears  to  have  been  known  to 
the  late  John  Hunter,  and  also  to  Cotunnius;  but  it  is  minutely  described  by 
Scarpa,  and  is  delineated  by  Soemmering  in  his  plate  of  the  nose — See 
“ Observations  on  certain  parts  of  the  Animal  Economy,”  by  J.  Hunter, 
page  219,  and  also  Scarpa  “ De  Organo  Olfactus.”  In  this  last  are  some 
interesting  observations  relative  to  the  ducts  of  Steno. 


332 


Third  Branch  of  the  Fifth  Pair . 

inferior  turbinated  bone.  When  it  arrives  at  the 
roof  of  the  mouth,  it  divides  into  several  branches 
which  run  forwards,  and  are  distributed  to  the  mem- 
brane which  lines  the  roof  of  the  mouth.  Some  of 
its  branches  pass  to  the  soft  palate,  the  uvula,  and 
the  tonsils;  small  filaments  pass  into  the  back  part  of 
the  upper  jaw. 

The  inferior  Maxillary  Nerve , or  the  Third  Branch 
of  the  Fifth  Pair , 

Passes  through  the  foramen  ovale  into  the  zygomatic 
fossa,  and  divides  into  two  branches , one  cf  which 
sends  ramifications  to  many  of  the  contiguous  mus- 
cles, as  the  Temporal,  the  Masseter,  the  Buccina- 
tor, the  Pterygoid  ; and  also  to  the  anterior  part  of 
the  ear  and  the  side  of  the  head.  The  other  branch 
passes  between  the  pterygoid  muscles,  and  divides 
into  two  ramifications,  one  of  which  proceeds  to  the 
tongue,  and  is  called  the  Lingual  or  Gustatory , 
while  the  other  passes  into  the  canal  of  the  lower 
jaw. 

The  Lingual  Nerve  proceeds  between  the  ptery- 
goid muscles,  and  in  its  course  is  joined  by  the 
chorda  tympani.  It  continues  forward  between  the 
maxillary  gland  and  the  lining  membrane  of  the 
mouth  ; and  passes  near  the  excretory  duct  of  that 
gland,  above  the  mylo-hyoideus  and  the  sublingual 
gland,  to  the  under  side  of  the  tongue,  near  the 
point : it  then  divides  into  a number  of  branches 
which  enter  into  that  body  between  the  genio-hyoi- 
deus  and  lingualis  muscles.  This  nerve  has  been 
supposed  to  be  particularly  concerned  in  the  function 
of  taste,  because  many  of  its  branches  continue  to 
the  upper  surface  of  the  tongue,  especially  near  the 
point.  In  its  course  it  has  a communication  with 
the  ninth  pair  of  nerves,  and  it,  sends  twigs  to  the 


The  Sixth  Pair  of  Nerves.  333 

membrane  of  the  mouth  and  gums,  and  the  contiguous 
parts. 

After  parting  with  the  lingual  nerve,  the  inferior 
maxillary  continues  to  the  upper  and  posterior  orifice 
of  the  canal  in  the  lower  jaw.  Before  it  enters  this 
canal  it  sends  a branch  to  the  sub-maxillary  gland, 
and  to  the  muscles  under  the  jaw.  It  then  enters  the 
canal,  attended  by  blood  vessels,  and  proceeds  along 
it  to  the  anterior  maxillary  foramen,  on  the  side  of  the 
.chin,  through  which  it  passes  out.  In  this  course  it 
sends  twigs  to  the  sockets  of  the  teeth,  and  generally 
supplies  all  the  large  and  one  of  the  small  grinders. 
Before  it  leaves  the  jaw  it  sends  a branch  forwards, 
which  supplies  the  remaining  teeth  on  the  side  to 
which  it  belongs.  After  passing  out,  through  the  an- 
terior foramen,  it  is  spent  upon  the  muscles  and  inte- 
guments of  the  front  of  the  cheek,  the  chin,  and  the 
under  lip. 

THE  SIXTH  PAIR  OF  NERVES 

Are  called  Motores  Externi.  They  arise  from  the 
commencement  of  the  medulla  oblongata,  and  pro- 
ceed forward  under  the  pons  Yarolii.  They  proceed 
through  the  dura  mater  on  the  inside  of  the  fifth  pair, 
and  appear  to  pass  through  the  cavernous  sinuses, 
but  are  enclosed  in  sheaths  of  cellular  membrane 
while  they  are  in  those  sinuses.  When  in  this  situa- 
tion they  are  near  the  carotid  arteries,  and  each  nerve 
sends  off  one  or  more  very  fine  twigs,  which  being 
joined  by  a twig  from  the  pterygoid  branch  of  the 
fifth  pair,  accompany  the  carotid  artery  through  the 
carotid  canal,  and  then  unite  themselves  to  the  upper 
extremity  of  the  upper  cervical  ganglion  of  the  in- 
tercostal nerve. 

The  sixth  pair  afterwards  pass  into  the  orbit  of  the 
eye,  each  through  the  foramen  lacerum  of  its  respective 


334  Composition  of  the  Seventh  Pair. 

side,  and  is  spent  upon  the  Rectus  Externus  or  Ab- 
ductor muscle  of  the  eye. 

THE  SEVENTH  PAIR  OF  NERVES 

Comprises  two  distinct  cords  which  have  very  differ- 
ent destinations;  and  have,  therefore,  been  considered 
as  different  nerves,  by  several  anatomists.  One  of 
these  cords  is  appropriated  to  the  interior  of  the  ear, 
and  is  the  proper  Auditory  Nerve.  The  other  is 
principally  spent  upon  the  face,  and,  therefore,  has 
been  called  the  Facial.  They  have,  however,  more 
frequently  been  denominated  the  Seventh  Pair , and 
distinguished  from  each  other,  in  consequence  of  a 
great  difference  in  their  texture,  by  the  appellations 
of  Portio  Dura  and  Portio  Mollis. 

These  two  cords  pass  off  nearly  in  contact  with 
each  other,  from  the  side  of  the  upper  part  of  the 
Medulla  Oblongata , where  it  is  in  contact  with  the 
pons  Varolii ; but  the  Portio  Mollis  can  be  traced  to 
the  fourth  ventricle,  while  the  Portio  Dura  is  seen  to 
rise  from  the  union  of  the  pons  Varolii  with  the  me- 
dulla oblongata  and  the  crura  Cerebelli.  The  Portio 
Dura , at  its*origin,  is  on  the  inside  of  the  Portio 
Mollis.  Between  these  cords  are  one  or  more  small 
fibres,  called  Portio  Media , which  seem  to  originate 
very  near  them,  and  finally  unite  with  the  Portio 
Dura. 

Each  of  the  seventh  pair  of  nerves,  thus  compo- 
sed, proceeds  from  its  origin,  to  the  Meatus  Audito- 
rius  Internus  of  the  temporal  bone  ; and  the  Portio 
Mollis  divides  into  fasciculi,  which  proceed  to  the 
different  parts  of  the  organ  of  hearing,  in  the  man- 
ner  described  in  the  account  of  the  ear.* 

The  Portio  Dura  enters  an  orifice  at  the  upper 
and  anterior  part  of  the  end  or  bottom  of  the  Meatus 


See  Vol.  I.  p.  SS6-. 


Chorda  Tymptmi^Pes  Ansennus.  33 5 

Audiiorius  Interims.  This  orifice  is  the  commence- 
ment of  a canal,  which  has  been  called  the  Aqueduct 
of  Fallopius,  and  proceeds  from  the  Meatus  Audit  o- 
rius  Intemus  to  the  external  foramen,  between  the 
mastoid  and  styloid  processes  at  the  basis  of  the  era- 
nium.  This  canal  first  carves  backwards  and  out- 
wards, near  to  the  upper  surface  of  the  petrous  bone,, 
then  forms  an  acute  angle,  and  proceeds,  (back- 
wards and  downwards,)  to  the  stylo-mastoid  foramen, 
passing  very  near  the  cavity  of  the  tympanum  in  its 
course. 

The  Portio  Dura,  as  it  passes  into  the  canal  from 
the  meatus  internus,  seems  to  receive  an  investment 
from  the  dura  mater.  It  fills  up  the  canal,  but  does  not 
appear  to  be  compressed.*  Near  the  angle  it  is  joined 
by  the  twig  of  the  vidian  nerve,  whieh  proceeds  from 
the  pterygoid  branch  of  the  fifth  pair,  and  enters  the 
petrous  bone  by  the  small  foramen  innommatum  on 
its  anterior  surface.  In  its  course  through  the  canal 
it  sends  off  some  very  small  twigs  to  the  muscles 
and  appurtenances  of  the  small  bones  of  the  ear,  and 
to  the  mastoid  cells ; and,  when  it  has  arrived  almost 
at  the  end  of  the  canal,  it  sends  off,  in  a retrograde 
direction,  a small  branch  which  proceeds  into  the  ca- 
vity of  the  tympanum,  (entering  it  by  a foramen  near 
the  base  of  the  pyramid,)  and  crosses  the  upper  part 
of  it,  near  the  membrana  tympani,  between  the  long 
processes  of  the  Malleus  and  Incus.  This  twig  is 
th eCorda  Tympani  ; it  proceeds  from  the  cavity,  by 
a fissure  on  the  outside  of  the  Eustachian  tube,  to 
join  the  lingual  branch  of  the  fifth  pair,  as  has  been 
already  mentioned.* 

The  Portio  Dura , after  passing  out  of  the  Fora- 

* The  late  John  Hunter  believed  that  the  chorda  tympani  is  merely  a 
continuation  of  the  twig  of  the  pterygoid  branch  which  joins  the  portio 
dura  above— See  Observations  on  certain  par's  of  the  Animal  Econcmv, 
220 


336  Composition  of  the  Eighth  Pair  of  Nerves* 

men  Stylo -Mastoideum , is  situated  behind  and  with- 
in the  parotid  gland.  Here  it  gives  small  twigs  to 
the  back  of  the  ear  and  head,  and  to  the  digastric 
and  stylo-hyoideus  muscles.  It  perforates  the  gland 
after  sending  filaments  to  it,  and  then  divides  into 
branches  which  are  arranged  in  such  a manner  that 
they  constitute  what  has  been  called  the  Pes  Jlnse- 
rinus. 

To  describe  the  various  branches  in  this  expan- 
sion would  be  more  laborious  than  useful.  Some  of 
them  are  spread  upon  the  temple  and  the  upper  part 
of  the  side  of  the  head,  and  unite  with  the  supra-or= 
bitar  branches  of  the  ophthalmic  nerve.  Some  pass 
above  and  below  the  eye,  and  are  distributed  to  the 
orbicularis  muscle,  and  communicate  with  nervous 
twigs  that  pass  through  foramina  in  the  malar  bone, 
&c.  Some  large  branches  pass  transversely.  They 
cross  the  masseter  muscle,  and  divide  into  ramifica- 
tions which  are  spent  upon  the  cheek  and  the  side  of 
the  nose  and  lips,  and  communicate  with  the  small 
branches  of  the  superior  maxillary  nerve. 

A large  number  of  branches  pass  downwards. 
Many  of  them  incline  forwards,  and  are  spent  on 
the  soft  parts  about  the  under  jaw ; while  others  pro- 
ceed below  the  jaw  to  the  superficial  muscles  and 
integuments  of  the  upper  part  of  the  neck,  communi- 
cating with  the  branches  of  the  contiguous  nerves.*' 

THE  EIGHTH  PAIR  OF  NERVES 

Are  very  frequently  denominated  the  Par  Vagum9 
on  account  of  their  very  extensive  distribution. 

* A most  minute  and  laboured  description  of  the  nerves  of  the  face  was 
published  by  the  celebrated  Meckel,  in  the  seventh  volume  of  Memoirs 
of  the  Royal  Academy  of  Sciences  of  Berlin,  for  the  year  1751,  accompa- 
nied with  a plate,  exhibiting  the'side  of  the  head,  of  three  times  the  natu- 
ral size.  This  is  republished  in  the  Collection  Academiaue : Partie 
Etrang6re.—' Tom.  viii. 


Composition  of  the  Eighth  Pair  of  Nerves.  337 

They  arise  from  those  portions  of  the  medulla  ob- 
longata which  are  denominated  the  Corpora  Olivaria . 
Each  nerve  consists  of  a cord,  which  is  anterior,  and 
called  the  Glosso Pharyngeal ; and  of  a considerable 
number  of  small  filaments,  which  arise  separately, 
but  unite  and  form  another  cord,  the  proper  Par  Fa- 
gum.  Associated  with  these  is  a third  cord,  called 
the  Spinal , or  Accessory  Nerve  of  Willis,  which  ori- 
ginates in  the  great  canal  of  the  spine,  and,  passing 
up  into  the  cavity  of  the  cranium,  goes  out  of  it  with 
these  nerves  through  the  foramen  lacerum. 

The  two  first  mentioned  nerves  proceed  from  their 
origin  to  the  posterior  foramen  lacerum,  and  pass 
through  it  with  the  Internal  Jugular  vein, — being 
separated  from  the  vein  by  a small  process  of  bone. 
They  are  also  separated  from  each  other  by  a small 
process  of  the  dura  mater.  In  the  foramen  they  are 
very  close  to  each . other  ; but  soon  after  they  have 
passed  through  it,  they  separate  and  proceed  towards 
their  different  destinations. 

The  Glosso -Pharyngeal  proceeds  towards  the 
tongue,  between  the  stylo-pharyngeus  and  the  stylo- 
glossus muscles,  following  the  course  of  the  last  men- 
tioned muscle  to  the  posterior  part  of  the  tongue.  At 
the  commencement  of  its  course  it  receives  a twig  from 
the  Portio  Dura  and  one  also  from  the  Par  Vagum. 
It  soon  gives  off  a branch  which  passes  down  on  the 
inside  of  the  common  carotid  to  the  lower  part  of  the 
neck,  where  it  joins  some  twigs  of  the  intercostal  to 
form  the  cardiac  nerves.  Afterwards  it  sends  off 
several  twigs  to  the  muscles  of  the  pharynx  and  its 
internal  membrane,  and  also  some  twigs  which  unite 
with  others  from  the  upper  cervical  ganglion  of  the 
Sympathetic , and  form  a network  that  lies  over  the 
anterior  branches  of  the  external  carotid.  The  Glosso- 
pharyngeal finally  enters  the  tongue,  at  the  termina- 

Vol.  ii.'  43 


338  Giosso- Pharyngeal  Nerve,*— Par  Vagum . 

tion  of  the  hyo-glossns  muscle ; and  after  sending 
t ranches  to  the  lingualis,  and  the  various  muscles  in- 
serted into  the  tongue,  terminates  in  small  ramifica- 
tions that  are  spent  upon  the  sides  and  middle  of  the 
root  of  the  tongue,  and  upon  the  large  papillae. 

THE  PAR  VAGUM 

Are  slightly  enlarged  after  passing  through  the  fora- 
men lacerum.  As  they  descend,  they  adhere  to  the 
superior  ganglion  of  the  intercostal,  and  also  to  the 
ninth  pair.  They  proceed  behind  and  on  the  outside 
of  the  carotid,  and  are  contained  in  the  same  sheath  of 
cellular  membrane  which  encloses  that  artery  and  the 
internal  jugular  vein.  Each  of  these  nerves,  soon 
after  it  leaves  the  cranium,  gives  a twig  to  the  glosso- 
pharyngeal ; that  soon  after  it  sends  off  a branch  called 
the  Pharyngeal,  which  unites  to  one  from  the  acces- 
sory nerve,  and  to  one  or  more  from  the  glosso-pha- 
ryngeal,  and  proceeds  to  the  middle  constrictor  of 
the  pharynx,  when  it  expands  into  ramifications  that 
form  a plexus  from  which  proceed  a number  of  small 
twigs  that  go  to  the  larynx,  and  some  that  pass  down 
on  the  common  carotid  artery. 

It  then  sends  off,  downward  and  forward,  the  Su- 
perior Laryngeal  nerve,  which  continues  in  that  di- 
rection behind  the  carotid  artery,  and  divides  into 
an  external  and  internal  branch. 

The  Internal  Branch , which  is  the  largest,  pro- 
ceeds between  the  os  hyoides  and  the  thyroid  carti- 
lage ; and  divides  into  numerous  ramifications  which 
are  distributed  to  the  arytenoid  muscles  and  to  the 
membrane  which  lines  the  larynx  and  covers  the  epi- 
glottis. It  is  said,  that  fine  twigs  can  be  traced  into 
the  foramina,  which  are  to  be  seen  in  the  cartilage 
of  the  epiglottis ; — some  ramifications  can  be  traced 
to  the  pharynx ; — others  communicate  with  the 
branches  of  the  recurrent  nerve. 


Superior  Laryngeal  Branch  of  the  Par  Vagum . 339 

The  External  Branch  sends  twigs  to  the  pharynx, 
to  the  lower  and  inner  part  of  the  larynx,  and  to  the 

thyroid  gland. 

In  its  course  downwards,  the  great  nerve  some- 
times sends  off  a twig,  which  unites  with  one  from 
the  ninth  pair  that  passes  to  the  sterno-hyoidei  and 
sterno-thyroidei  muscles. 

It  uniformly  sends  off  one  or  more  twigs,  which 
pass  into  the  thorax  and  combine  with  small 
branches  from  the  sympathetic  or  intercostal  nerve, 
to  form  the  Cardiac  plexus , which  sends  nerves  to 
the  heart. 

After  entering  the  thorax,  the  right  trunk  of  the 
Par  Vagum  passes  before  the  subclavian  artery ; and 
the  left  trunk  before  the  arch  of  the  aorta  ; and  im- 
mediately after  passing  these  arteries,  each  of  the 
nerves  divides  into  an  interior  and  posterior  branch. 
The  anterior  is  the  continuation  of  the  Par  Vagum ; 
the  posterior  is  a nerve  of  the  Larynx;  which,  from 
its  retrograde  course,  is  called  the  Recurrent  Nerve. 

On  the  left  side  the  Recurrent  Nerve  winds  back- 
wards round  the  aorta,  and  on  the  right  side  round 
the  subclavian  artery,  and  proceeds  upwards,  deeply 
seated,  on  the  side  of  the  trachea,  to  the  Latnjnx. 
Soon  after  its  origin  it  sends  filaments  to  a ganglion 
of  the  sympathetic,  to  the  cardiac  plexus,  and  to  a 
pulmonary  plexus  soon  to  be  mentioned.  In  its 
course  upwards  it  sends  twigs  to  the  trachea  and  the 
oesophagus.  It  proceeds  behind  the  thyroid  gland, 
and  sends  twigs  to  that  organ.  At  the  lower  part  of 
the  larynx  it  sends  off  a branch  which  communicates 
with  branches  of  the  superior  laryngeal  nerve.  It 
also  divides  into  branches  which  are  spread  upon  the 
posterior  crico-arytenoid,  and  the  arytenoid  muscles : 
and  also  upon  the  lateral  crico-arytenoid  and  the 
thvro-arytenoid  muscles,  as  well  as  upon  the  mem- 


340  Recurrent  Branch  of  the  Par  Vagum. 

brane  which  lines  the  hack  part  of  the  larynx  and  the 
contiguous  surface  of  the  pharynx. 

There  is  a difference  in  the  arrangement  of  the  re- 
currents on  the  different  sides  in  consequence  of  one 
winding  round  the  aorta,  while  the  other  winds  round 
the  subclavian  artery. 

After  sending  off  the  recurrents,  each  trunk  of  the 
par  vagum  proceeds  behind  the  ramifications  of  the 
trachea ; but  previously  detaches  some  small  branches, 
which  are  joined  by  twigs  from  the  intercostal  and 
from  the  recurrent,  and  form  a plexus  upon  the  an- 
terior part  of  the  vessels  going  to  the  lungs.  This 
Anterior  plexus,  after  sending  off  some  minute 
branches  to  the  cardiac  nerves  and  the  pericardium, 
transmits  its  branches  with  the  bronchia  and  the 
blood  vessels,  into  the  substance  of  the  lungs. 

Some  of  the  branches  which  proceed  from  the  par 
vagum,  pass  down  on  the  posterior  part  of  the  tra- 
chea, and  enter  into  the  membrane  which  forms  it, 
and  the  mucous  glands  which  are  upon  it ; and  some 
pass  to  the  oesophagus. 

When  the  par  vagum  is  behind  the  great  vessels 
of  the  lungs,  a number  of  branches  go  off  transverse- 
ly, and  are  also  joined  by  some  fibres  from  the  sym- 
pathetic. These  form  the  Posterior  pulmonary 
plexus ; the  ramifications  from  which  proceed  into 
the  substance  of  the  lungs,  and  are  principally  spent 
upon  the  ramifications  of  the  bronchia.  It  has  been 
said,*  that  the  small  twigs  into  which  they  divide, 
very  generally  penetrate  into  the  small  ramifications 
of  the  bronchia,  and  are  spent  upon  their  internal 
membrane. 

Soon  after  sending  off  the  nerves  of  the  pulmona- 
ry plexus,  the  Par  Vagum  proceed  dow’nwards 

* See  Buisson,  in  the  continuation  of  the  Descriptive  Anatomy  of 
Bichat. 


Different  Functions  of  the  Laryngeal , fye.  341 

upon  the  oesophagus;  the  left  nerve  being  situated 
anteriorly,  and  the  right  posteriorly.  Each  of  these 
nerves  forms  a plexus  so  as  nearly  to  surround  the 
oesophagus,  as  they  descend  on  it;  but  the  net- work 
is  thickest  on  the  posterior  side.  They  pass  through 
the  diaphragm  with  the  (esophagus,  and  unite  again 
so  as  to  form  considerable  trunks. 

The  Anterior , which  is  the  smallest,  proceeds  along 
the  lesser  curvature  of  the  stomach  to  the  pylorus. 
Some  of  its  fibres  are  spread  upon  the  anterior  side 
of  the  stomach  and  the  lesser  omentum.  Others  of 
them  extend  to  the  left  hepatic,  and  also  to  the  solar 
plexus. 

The  Posterior  trunk  sends  branches  to  surround 
the  cardiac  orifice  of  the  stomach.  Many  branches 
are  spread  upon  the  under  side  of  the  great  curvature 
of  the  stomach.  Some  of  them  pass  in  the  course  of 
the  coronary  artery  to  the  cceliac,  and  unite  to  the 
hepatic  and  splenic  plexuses;  and  one  trunk,  which 
is  thick,  although  short,  proceeds  to  the  solar  plexus. 

The  Accessory  Nerve  of  Willis , 

Which  has  been  mentioned  as  associated  with  the 
eighth  pair  of  nerves,  within  the  cranium,  has  a very 
peculiar  origin. 

It  arises  by  small  filaments,  which  come  off  from 
the  spinal  marrow,  between  the  anterior  and  posteri- 
or fasciculi  of  the  cervical  nerves,  and  proceeds  up- 
wards to  the  great  occipital  foramen,  between  these 
fasciculi.  It  commences  sometimes  at  the  sixth  or 
seventh  cervical  vertebra,  and  sometimes  about  the 
fourth.  It  enters  the  cavity  of  the  cranium  through 
the  foramen  magnum,  and  proceeds  upwards  and  out- 
wards, so  as  to  join  the  eighth  pair  of  nerves  at  some 
distance  from  its  origin,  and  in  this  course  it  receives 
filaments  from  the  medula  oblongata. 

After  approaching  very  near  to  the  eighth  pair  of 


342 


JYinth  Pair  of  jYerves. 

nerves,  it  accompanies  it  to  the  foramen  lacerum,  and 
passes  out  in  its  own  separate  sheath.  It  then  leaves 
the  eighth  pair  and  descends  towards  the  shoulder, 
proceeding  through  the  sterno-mastoid  muscle.  Soon 
after  it  emerges  from  the  cranium,  it  sends  a ramifi- 
cation to  the  pharyngeal  branch  of  the  Par  Vagurn 
and  another  to  the  par  vagum  itself.  After  passing- 
through  the  upper  and  back  part  of  the  sterno-mastoid 
muscle,  it  terminates  in  the  trapezius.  It  adheres 
to  the  ninth  pair  of  nerves  as  it  passes  by  it,  and 
sends  a twig  to  the  sub-occipital  and  some  of  the 
cervical  nerves.  It  also  gives  ramifications  to  the 
sterno-mastoid  muscle  as  it  passes  through  it. 

It  has  already  been  stated  that  the  Laryngeal  and  Re- 
current Nerves  appear  to  answer  different  purposes  in 
their  distribution  to  the  Larynx. — When  both  of  the 
recurrent  nerves  are  divided  in  a living  animal,  the 
voice  seems  to  be  lost.  When  the  laryngeal  nerves 
only  are  divided,  the  strength  of  the  voice  remains, 
but  it  is  flatter.  The  recurrent  nerves,  therefore,  seem 
essential  to  the  formation  of  the  voice.  The  laryngeal 
nerves  are  necessary  to  its  modulation. 

The  history  of  the  investigation  of  this  subject  is 
contained  in  Mr.  Haighton’s  paper  in  the  third 
volume  of  Memoirs  of  the  Medical  Society  of 
London. 

THE  NINTH  PAIR  OF  NERVES. 

Each  of  these  nerves  arises  from  the  groove  in  the 
medulla  oblongata,  between  the  corpora  pyramidalia 
and  the  corpora  olivaria.  Three  or  four  fasciculi,  of 
distinct  filaments,  unite  to  form  it.  Thus  composed, 
it  proceeds  to  the  anterior  condyloid  foramen  of  the 
occipital  bpne,  and  passes  through  the  dura  mater. 
It  seems  firmly  united,  by  the  cellular  membrane,  to 
the  eighth  pair,  and  to  the  first  ganglion  of  the  sym- 
pathetic, soon  after  it  passes  from  the  occipital  bone. 
It  is  either  connected  to  the  sub-occipital  nerve  by  a 
small  ramification,  or  it  joins  a branch  which  pro 


343 


Ninth  and  Tenth  Pair  of  Nerves . 

eeeds  from  the  sub-occipital  to  the  cervical,  and 
bends  round  the  transverse  process  of  the  atlas.  It 
passes  between  the  internal  carotid  artery  and  the 
internal  jugular  vein,  and  crosses  the  external  caro- 
tid at  the  origin  of  the  occipital  artery.  At  this 
place  it  generally  sends  downwards  a large  branch 
which  is  called  the  Descendens  Noni.  Passing  for- 
wards, it  is  on  the  outside  of  the  posterior  portion 
of  the  digastric  muscle,  and  inclines  downwards ; but 
near  the  tendon  of  the  muscle  it  turns  upwards,  and 
proceeds  on  the  inside  of  the  mylo-hyoideus,  where 
it  divides  into  ramifications,  which,  at  the  anterior 
edge  of  the  hyo  glossus  muscle,  begin  to  enter  into 
the  substance  of  the  tongue,  between  the  genio-glos- 
sus  and  the  lingualis  muscles. 

Some  of  the  branches  of  this  nerve  unite  with 
those  of  the  lingual  branch  of  the  fifth  pair.  Others 
are  distributed  to  almost  all  the  muscles  connected 
with  the  tongue. 

The  branch  called  descendens  noni  passes,  down 
in  the  course  of  the  common  carotid  artery,  and 
sends  branches  in  its  progress  to  the  upper  portions 
of  the  eoraco-hyoidei  and  sterno- thy  roidei  muscles; 
it  unites  with  ramifications  of  various  sizes  from  the 
first,  second  and  third  cervical  nerves,  which  form  a 
bow  under  the  sterno- mastoid  muscle,  from  which 
ramifications  go  to  the  lower  portions  of  the  sterno- 
byoidei  and  thyroidei  muscles  and  of  the  coraco- 
hyoidei. 

OF  THE  CERVICAL  NERVES. 

The  tenth  or  last  pair  of  the  head,  commonly  call- 
ed the  Sub  occipital , may  be  arranged  with  these 
nerves,  because  they  arise*  like  them,  from  the  me- 
dulla spinalis,  and  are  distributed  to  the  muscles  on 

the  neck. 


344  Siib-Oceipitul  or , Tenth  pair  of  Serves, 

The  sub-occipital  JYet'vcs 

Arise  on  each  side  of  the  spinal  marrow,  nearly  op- 
posite to  the  interval  between  the  great  foramen  of 
the  os  occipitis  and  the  atlas. 

Each  of  these  nerves  consists  of  an  anterior  and 
posterior  fasciculus,  or  bundle  of  fibres,  which  pass 
outwards  immediately  under  the  vertebral  arteries, 
and  form  a ganglion,  from  which  proceeds  an  ante- 
rior and  a posterior  branch. 

The  anterior  branch  is  united  to  the  second  cervi- 
cal nerve  below,  and  to  the  ninth  nerve,  or  the  hy- 
po-glossal,. above.  It  also  sends  filaments  to  the  up- 
per ganglion  of  the  great  sympathetic  nerve. 

The  posterior  branch  is  spent  upon  the  Recti>  the 
Obiiqui,  and  some  other  muscles  of  the  head. 

The  proper  Cervical  Nerves  consist  of  seven  pair; 
of  which  the  first  six  go  off  between  the  vertebrae  of 
the  neck,  and  the  seventh  between  the  last  of  the 
neck  and  the  first  of  the  back. 

The  first  cervical  JYerve 

Passes  out  between  the  atlas  and  the  Vertebra  Den - 
tata.  It  originates  from  two  fasciculi,  which  are 
connected  to  each  other  at  a ganglion,  and  then  sepa- 
rate into  an  anterior  and  a posterior  branch.* 

The  anterior  branch  is  connected  by  filaments  with 
the  accessory  nerve,  with  the  ninth  pair  of  the  head, 
and  with  the  upper  ganglion  of  the  sympathetic.  It 
is  also  connected  with  the  second  cervical  nerve ; and 
sends  some  branches  to  the  muscles  on  the  anterior 
part  of  the  spine. 

The  posterior  branch,  after  communicating  with 
the  posterior  branches  of  the  sub-occipital  and  the 

* This  arrangement  is  common  to  the  nerves  of  (he  spine.  The  ganglion 
is  formed  by  the  posterior  fasciculus. 


Cervical  and  Phrenic  JVerves,  345 

second  nerves  of  the  neck,  perforates  the  complexus 
muscle,  and  ascending  upon  the  back  of  the  head,  is 
distributed  with  the  occipital  artery. 

THE  SECOND  CERVICAL  NERVE 

Sends  off,  from  its  Anterior  Branch , a twig  which 
descends  to  the  lowrer  cervical  ganglion  of  the  sympa- 
thetic, and  a considerable  ramification  to  the  third  cer- 
vical nerve.  It  also  sends  off  some  twigs  to  the  sterno- 
mastoid  muscle,  and  others  to  join  the  accessory  nerve. 
Some  of  its  small  ramifications  pass  down  upon  the 
external  jugular  vein,  and  others  unite  with  the  de- 
scending branch  of  the  ninth  pair  of  the  head.  A 
small  branch  is  also  concerned  in  the  formation  of  the 
phrenic  nerve.  Two  larger  branches  of  this  nerve 
wind  round  the  posterior  edge  of  the  sterno-mastoid, 
and  are  spread  under  the  integuments  of  the  anterior, 
lateral  and  posterior  parts  of  the  neck  and  lower  parts 
of  the  head;  they  have  a communication  with  the 
portio  dura  of  the  seventh  pair.*— The  posterior 
branch  of  this  nerve  is  spent  upon  the  extensor  mus- 
cles of  the  head  and  neck. 

The  THIRD  CERVICAL  NERVE 

Sends  down,  from  its  Anterior  Branch , the  princi- 
pal trunk  of  the  phrenic  nerve.  It  also  sends  twigs 
to  the  fourth  cervical,  to  the  lower  cervical  ganglion 
of  the  intercostal,  and  to  the  descending  branch  of 
the  ninth  of  the  head.  Some  of  its  branches,  unite 
with  twigs  of  the  accessory  nerve,  and  others  are 
spent  upon  the  muscles  and  integuments  of  the  shoul- 
der and  lower  part  of  the  neck.  A small  Posterior 
Branch  is  spent  upon  the  muscles  of  the  back  of  the 
neck. 

* These  superficial  branches  have  sometimes  been  described  as  coming 
from  a plexus  ; but  they  often  arise  directly  from  the  Second  Cervical 
nerve. 

VOL,  If, 


44 


346  Cervical  JVerve$, 

THE  NERVES  OF  THE  DIAPHRAGM 

Are  generally  denominated  the  Phrenic.  The  prin- 
cipal root  of  each  of  them  is  commonly  derived  from 
the  third  cervical  nerve,  but  frequently  the  second  and 
the  fourth  cervical  nerves  contribute  to  the  forma- 
tion ; and  they  are  sometimes  joined  by  a twig  which 
is  derived  from  the  ninth  pair. 

Each  nerve  proceeds  down  the  neck,  between  the 
rectus  capitis  major  and  the  scalenus  anticus,  and 
continues  along  the  fore  part  of  the  scalenus  anticaS; 
it  descends  into  the  thorax  within  the  anterior  end  of 
the  first  rib,  between  the  subclavian  vein  and  the  ar- 
tery. It  sometimes  receives  a twig  from  the  fifth  cer- 
vical nerve,  and  a twig  passes  between  it  and  the  great 
sympathetic.  After  entering  the  thorax,  they  descend, 
attached  to  the  mediastinum,  before  the  root  of  the 
lungs.  In  consequence  of  the  projection  of  the  point 
of  the  heart  to  the  left,  the  course  of  the  left  is  a little 
different  from  that  of  the  right;  that  of  the  right  pro- 
ceeding in  a more  perpendicular  direction.  When 
they  arrive  at  the  diaphragm,  they  divide  into  many 
ramifications,  which  have  a radiated  arrangement,  and 
terminate  on  the  fibres  of  that  muscle,  both  on  the 
upper  and  lower  surface.  Some  fibres  from  each 
nerve  are  continued  downward,  and  communicate  in 
^ the  abdomen  with  fibres  from  the  intercostal, 

THE  FOURTH,  FIFTH,  SIXTH,  AND  SEVENTH  CERVI- 
CAL NERVES, 

May  be  comprised  in  one  description.  They  pass 
off  successively  from  the  Medulla  Spinalis*  between 
the  vertebrae,  like  the  other  nerves.  Their  Posterior 
Branches  are  generally  distributed  to  the  back  of  the 
neck,  and  are  very  small.  Their  Anterior  Branches 
are  principally  appropriated  to  the  upper  extremi- 
ties, and  are  large.  They  generally  send  each  a 


Remaining  Cervical  Nerves.- —^Brachial  Plexus . 347 

small  twig  to  the  lower  cervical  ganglion  of  the  inter- 
costal nerve,  and  a few  small  branches  to  some  of  the 
contiguous  muscles.  They  are  arranged  and  com- 
bined so  as  to  form  the  net-work,  now  to  be  described, 
which  is  called  the  Brachial  or  Axillary  plexus ; 
and,  in  the  formation  of  this  plexus,  they  are  joined 
by  the  first  dorsal  nerve. 

The  BRACHIAL  PLEXUS 

Extends  from  the  lower  part  of  the  side  of  the  neck, 
into  the  arm-pit.  It  commences  in  the  following 
manner.  The  fourth  and  fifth  cervical  nerves  pro- 
ceed downwards,  and  after  uniting  to  each  other 
about  an  inch  and  a half  below  their  egress  from  the 
spine,  they  separate  again,  almost  immediately,  into 
two  branches. 

The  sixth  cervical  nerve,  after  passing  downwards, 
divides  also  into  two  branches,  one  of  which  unites 
with  the  uppermost  branch  that  proceeds  from  the 
union  of  the  fourth  and  fifth,  and  the  other  with  the 
lowermost,  and  they  all  proceed  downwards. 

The  seventh  cervical  is  joined  by  the  first  dorsal, 
which  proceeds  upwards,  and  unites  with  it  at  a 
short  distance  from  the  spine.  The  cord  produced  by 
their  junction  soon  unites  with  one  of  the  cords  above 
described.  As  these  different  cords  proceed  down- 
wards, they  divide,  and  their  branches  again  unite. 
The  axillary  artery,  which  passes  in  the  same  direc- 
tion, is  surrounded  by  them.  In  this  manner  the 
axillary  plexus  is  often  formed. 

The  muscles  about  the  shoulder,  both  before  and 
behind,  are  supplied  by  the  axillary  plexus.  Thus, 
it  sends  branches  to  the  Sub -scapular  is,  Teres  Major , 
and  Latissimus  Dorsi,  behind;  and  to  the  Pect ora- 
lis Major  and  Minor , and  the  Mamma,  before.  It 
also  sends  off  a branch  called  the  Scapularis , which 


348 


Nerves  of  the  Arm . 

commonly  arises  from  the  upper  part  of  the  plexus, 
and  proceeds  through  the  notch  in  the  upper  costa 
of  the  scapula,  to  the  supra  and  infra  spinatus,  teres 
minor,  &c. 

Nerves  of  the  Arm. 

All  the  great  nerves  of  the  arm  are  derived  from 
the  axillary  plexus.  There  are  six  of  them,  which 
are  denominated  The  Musculo  Cutaneous  ; the  Me- 
dian The  Cubital , or  Ulnar  ; The  Internal  Cu- 
taneous; The  Radial  or  Muscular  Spiral ; and  the 
Circumflex  or  Articular. 

The  Musculo  Cutaneous,  or  Perforating  Nerve , 
passes  obliquely  through  the  upper  part  of  the  coraco 
brachialis  muscle.  Before  it  enters  the  muscle,  it 
sends  a branch  to  it.  After  leaving  the  muscle,  it 
passes  down  the  arm  between  the  biceps  and  the 
brachialis  internus,  to  which  it  also  gives  branches. 
It  proceeds  to  the  outside  of  the  biceps,  and  conti- 
nues under  the  median  cephalic  vein  to  the  anterior 
and  external  part  of  the  fore -arm  ; along  which  it 
passes,  under  the  integuments.  On  the  lower  part 
of  the  fore-arm  it  divides  into  many  branches,  which 
extend  to  the  root  of  the  thumb  and  the  back  of  the 
hand,  and  terminate  in  the  integuments. 

The  Median  Nerve,  which  is  one  of  the  largest  of 
the  arm,  often  proceeds  from  the  axillary  plexus  next 
to  the  musculo  cutaneous ; it  passes  dow  n the  arm, 
very  near  the  humeral  artery,  within  the  edge  of  the 
biceps  flexor  muscle,  and,  during  this  course,  gives 
off  no  branches  of  any  importance.  After  passing 
the  bend  of  the  elbow,  it  proceeds,  under  the  apo- 
neurosis of  the  biceps,  between  the  brachialis  inter- 
ims and  the  pronator  teres,  and  continues  down  near 


Sometimes  called  Radial. 


Median  and  Cubital  or  Ulnar  Nerves.  349 

the  middle  of  the  fore-arm,  between  the  flexor  subli- 
mis  and  the  flexor  profundus.  At  the  elbow  it  sends 
branches  to  several  muscles  on  the  anterior  side  of 
the  fore-arm,  and  to  the  integuments.  Among  these 
branches  is  one,  called  the  Interosseal  Nerve,  which 
passes  down  on  the  anterior  surface  of  the  interos- 
seal ligament,  with  the  artery  of  that  name.  This 
nerve  sends  branches,  in  its  course,  to  the  long  flexor 
of  the  thumb  and  the  deep  flexor  of  the  fingers. 
When  it  arrives  at  the  pronator  quadratus,  it  sends 
branches  to  that  muscle,  and,  passing  between  it  and 
the  interosseous  ligament,  perforates  the  liganient, 
and  soon  terminates  on  the  posterior  side  of  the  wrist 
and  hand. 

As  the  Median  Nerve  proceeds  downwards,  it  be- 
comes more  superficial  ; and  continuing  among  the 
tendons  of  the  flexors  of  the  fingers,  it  gives  off  a 
branch  which  is  principally  spent  upon  the  integuments 
of  the  palm  of  the  hand.  This  great  nerve  passes  with 
the  tendons  under  the  annular  ligament ; and  imme- 
diately after,  while  it  is  covered  by  the  Aponeurosis 
Palmaris,  and  by  that  portion  of  the  artery  which  is 
called  Arcus  Sublimis,  it  divides  into  branches,  which 
separate  from  each  other  at  acute  angles,  and  subdi- 
vide so  as  to  send  a ramification  to  each  side  of  the 
thumb,  of  the  index,  and  of  the  middle  finger  ; and 
to  the  radial  side  of  the  ring  finger. 

The  Cubital  or  Ulnar  Nerve  is  also  of  considera- 
ble size.  It  passes  down  on  the  inside  of  the  triceps 
extensor  muscle,  to  the  great  groove  formed  by  the 
olecranon  process  and  the  internal  condyle  of  the  os 
humeri ; and  in  this  course  it  often  sends  a branch  to 
the  triceps,  and  some  smaller  twigs  to  the  upper  part 
of  the  fore -arm.  From  the  groove  it  proceeds  on  the 
anterior  part  of  the  fore-arm,  between  the  flexor  carpi 
ulnaris  and  the  flexor  sublimis,  to  the  wrist.  At  a 
small  distance  above  the  wrist  it  sends  off  a branch, 


350  Radial,  or  Muscular  Spiral  Nerve. 

called  the  Dorsalis,  which  passes  between  the  flexor 
ulnaris  and  the  ulna,  to  the  back  of  the  fore-arm  and 
wrist,  where,  after  sending  ramifications  to  the  inte- 
guments and  contiguous  parts,  it  divides  into  branches 
which  pass  to  the  little  finger  and  the  finger  next  to 
it.  Those  branches  send  off,  in  their  course,  many 
twigs  which  pass  to  the  skin  and  cellular  sub- 
stance. 

The  ulnar  nerve  then  proceeds  with  the  artery, 
over  the  annular  ligament,  on  the  radial  side  of  the 
os  pisiforme,  and  divides  into  two  branches ; one  of 
which  is  superficial,  and  the  other  deep-seated. 

The  Superficial  divides  into  two  principal  branches, 
an  external  and  an  internal.  The  external  passes 
under  the  aponeurosis  palmaris  ; and,  after  sending 
a branch  to  combine  with  one  from  the  median,  and 
some  twigs  to  the  contiguous  muscles,  it  subdivides 
into  two  branches,  one  of  which  goes  to  the  ulnar 
side  of  the  ring  finger  and  the  opposite  side  of  the 
little  finger.  The  other  branch  sends  off  some  twigs 
to  the  muscles,  and  proceeds  along  the  ulnar  side  of 
the  little  finger. 

The  Deep-seated  palmar  branch  of  the  ulnar  nerve, 
passes  between  the  muscles  of  the  little  finger,  under 
the  tendons  of  the  flexors,  and  accompanies  the  deep- 
seated  arterial  arch  in  the  palm  of  the  hand,  giving 
branches  to  the  interossei,  and  other  contiguous  mus- 
cles. 

The  Radial  or  Muscular  Spiral  nerve  is  one  of 
the  largest  nerves  of  the  arm.  It  passes  from  the 
axillary  plexus  downward,  backward  and  outward, 
under  the  triceps  muscle,  to  the  external  side  of  the 
os  humeri.  In  this  course  it  gives  off  several  branches 
to  the  different  portions  of  the  triceps.  It  also  fre- 
quently gives  off  a large  branch,  which  passes  down- 
wards on  the  outside  of  the  olecranon,  to  the  back 
of  the  fore-arm.  and  continues  to  the  back  of  the 


Radial , ar  Muscular  Spiral  Nerve.  351 

hand,  furnishing  many  branches  which  terminate  in 
the  integuments.  It  then  proceeds  downwards  be- 
tween  the  supinator  radii  longus  and  the  brachialis 
interims.  Immediately  after  passing  the  articulation 
of  the  elbow,  it  divides  into  two  branches,  denomi- 
nated the  Superficial  and  the  , Profound.  The  Su- 
perficial soon  joins  the  radial  artery,  and  proceeds 
downwards,  sending  branches  to  the  contiguous  mus- 
cles. In  its  course  about  the  middle  of  the  arm,  it 
crosses  the  tendon  of  the  supinator  longus,  and  pro- 
ceeds between  it  and  the  tendon  of  the  extensor  carpi 
radialislongior ; itsoon  after  divides  the  two  branches, 
which  are  principally  distributed  to  the  thumb  and 
fore  finger,  and  also  to  the  integuments. 

The  Profound  branch  proceeds  to  the  back  of  the 
fore-arm  under  the  radial  extensor,  and  continues  to 
the  back  of  the  wrist  and  hand.  Into  this  course  it 
divides  into  two  branches,  which  are  distributed  to 
the  contiguous  muscles  and  tendons,  and  the  inte- 
guments. 

The  Internal  Cutaneous  nerve  is  the  smallest  of 
the  nerves  which  proceed  from  the  axillary  plexus. 
It  descends  in  the  course  of  the  basilic  vein,  and 
very  near  it.  Above  the  elbow  it  divides  into  an 
Internal  branch,  which  proceeds  over  the  Basilic 
Vein,  and  separates  into  branches  that  pass  down 
on  the  side  of  the  fore-arm ; and  an  External  Branch 
that  passes  under  the  Median  Basilic  Vein,  and  con- 
tinues down  on  the  anterior  part  of  the  fore-arm. 

The  Articular  or  Circumflex  nerve  proceeds 
backwards  from  the  plexus,  between  the  teres  major 
and  minor,  and  passes  nearly  around  the  body  of  the 
os  humeri,  at  a small  distance  below  its  head.  It  is 
distributed  to  the  contiguous  muscles  and  to  the  arti- 
culation ; but  its  principal  branches  terminate  in  the 
deltoid  muscle. 


352 


The  Dorsal  JYerves. 


THE  DORSAL  JYERVES 

Proceed  from  the  cavity  of  the  spine  between  the 
dorsal  vertebrae.  They  are  sometimes  called  Inter - 
costals,  because  they  pass  between  the  ribs,  like  the 
blood  vessels  of  that  name.  There  are  twelve  pair 
of  them,  and  they  are  named  numerically,  beginning 
from  above. 

These  nerves  proceed  from  the  medula  spinalis 
by  two  fasciculi  of  fibres — one  from  each  of  its  late- 
ral portions — the  posterior  fasciculus  is  the  largest. 
After  passing  through  the  lateral  foramen  and  the 
dura  mater,  a ganglion  is  formed  by  the  posterior 
fasciculus  : the  anterior  fasciculus  unites  to  this  gang- 
lion at  its  external  extremity:  and  one  nerve  is 
formed,  which  almost  immediately  divides  into  an 
anterior  and  a posterior  branch,  of  which  the  ante- 
rior is  the  largest. 

The  posterior  branch  proceeds  backwards,  and  is 
distributed  to  the  muscles  of  the  back.  The  anterior 
branch  passes  towards  the  angle  of  the  rib,  in  con- 
tact with  the  pleura.  Soon  after  its  origin,  this  an- 
terior branch  sends  off  two  ramifications  which  unite 
to  the  intercostal  nerve,  at  the  ganglion ; it  then  pro- 
ceeds forwards  with  the  blood  vessels,  between  the 
internal  and  external  intercostal  muscles,  in  the 
groove  near  the  lower  margin  of  the  ribs ; and  ter- 
minates on  the  anterior  part  of  the  thorax.  In  its 
course  it  sends  branches,  not  only  to  the  intercostal 
muscles  and  pleura,  but  to  the  other  muscles  and  the 
integuments  of  the  thorax. 

Some  of  the  dorsal  nerves  differ  from  the  others, 
as  to  the  ramifications  which  they  send  off. 

The  first  nerve , of  this  order,  joins  the  lower  cer- 
vical nerves  in  the  axillary  plexus  ; but  it  sends  off 
the  ramifications  to  the  sympathetic ; and  also  a 


General  Account  of  the  Lumbar  Nerves.  353 

branch,  which  passes  under  the  first  rib,  like  the 
other  dorsal  nerves. 

The  second  nerve,  sends  off  a branch,  which  passes 
through  the  external  intercostal  muscle  into  the  ax- 
illa, and  combines  there  with  a branch  of  the  cuta- 
neous nerve,  being  distributed  to  the  internal  and 
posterior  part  of  the  arm. 

The  third  dorsal  nerve  also  sends  off  a branch, 
which  is  distributed  to  the  axilla  and  the  back  part 
of  the  arm. 

These  branches  of  the  second  and  third  dorsad 
nerves,  are  called  intercosto-humeral  nerves. 

The  lower  dorsal  nerves  supply  the  muscles  and 
integuments  of  the  abdomen. 

Of  the  L UMBAR  Nerves . 

There  are  five  pair  of  these  nerves.  The  first  of 
them  passes  off  between  the  first  and  second  of  the 
lumbar  vertebras,  and  the  others  succeed  regularly  ; 
so  that  the  last  pair  is  situated  between  the  last  lum- 
bar vertebra  and  the  sacrum. 

The  first  lumbar  nerves  arise  from  the  medulla 
spinalis,  before  it  forms  the  cauda  equina  ; the  other 
four  pair  are  formed  by  the  cauda  equina. 

They  commence  by  anterior  and  posterior  fascicu- 
li, which  are  united  at  a ganglion.  From  these  gang- 
lion, anterior  and  posterior  branches  go  off,  which 
are  very  different  in  size,  the  anterior  being  the 
largest. 

The  posterior  branches  are  distributed  to  the  mus- 
cles of  the  back.  The  anterior  sends  branches  to  the 
ganglions  of  the  sympathetic  nerve,  and  also  commu- 
nicate with  each  other  to  form  the  Lumbar  Plexus , 
which  is  situated  on  the  lateral  parts  of  the  bodies  of 
the  Lumbar  Vertebrae,  before  their  transverse  pro- 
cesses, and  supplies  nerves  to  the  muscles  of  the 
thigh. 

Vol.  II, 


45 


354  Lumbar  JYerves. —Lumbar  Plexus . 

THE  FIRST  LUMBAR  NERVE 

Is  connected,  by  its  anterior  branch,  to  the  last  dor- 
sal  and  the  second  lumbar.  From  the  same  branch, 
ramifications  go  off  to  the  Quadratus  Lumborum,  and 
obliquely  across  that  muscle,  to  the  lower  part  of  the 
abdominal  muscles  near  the  spine  of  the  ilium. 

THE  SECOND  LUMBAR  NERVE 

Sends  off  a muscular  branch  downwards  and  out- 
wards : it  also  sends  off  the  small  branch,  called  the 
External  Spermatic,  which  passes  down  in  such  a 
direction,  that  it  perforates  the  transversalis  and  the 
obliquus  internus  muscles,  near  their  lower  margin, 
at  a small  distance  from  the  superior  anterior  spine 
of  the  ilium,  and  then  proceeds  within  the  lower  edge 
of  the  tendon  of  the  external  oblique  to  the  abdomi- 
nal ring,  through  which  it  passes.  In  the  male  it  is 
distributed  to  the  spermatic  cord  and  scrotum,  and  in 
the  female,  to  the  labia  pudendi.  In  the  female  it 
also  sends  a branch  to  the  uterus.*  The  Second 
Lumbar,  after  sending  off  these  branches,  passes 
downwards,  and  joins  the  Third  lumbar  nerve.  From 
this  union  of  the  second  and  third  nerves,  a branch 
called  the  Cutaneus  Medius,  which  will  be  soon  de- 
scribed proceeds  downwards. 

After  sending  off  this  branch,  the  united  trunk  of 
the  second  and  third  joins  the  Fourth  ; and  from  this 
union  is  sent  off  the  Obturator  Nerve,  which  passes 
through  the  aperture  in  the  membrane  that  closes 
the  foramen  thyroideum  ; the  Crural  Nerve,  which 
passes  under  Poupart’s  ligament ; and  a third  branch 
that  proceeds  downwards,  and  joins  the  Fifth  lumbar 
nerve.  The  Fifth  lumbar  nerve,  with  this  acces- 
sion from  above,  descends  into  the  pelvis,  and  unites 
with  the  sacral  nerves. 


The  external  spermatic  often  comes  off  from  the  first  lumbar  nerve 


355 


Obturator  Nerve.— Crural  Nerve . 

This  arrangement  of  the  lumbar  nerves  constitutes 
the  Lumbar  Plexus , which,  as  has  been  already  sta- 
ted, furnishes  three  nerves  to  the  lower  extremity, 
viz.  the  Cutaneus  Medius , the  Obturator , and  the 
Crural  Nerve . 

The  Cutaneus  Medius , which  arises  from  the 
union  of  the  second  and  third  nerves,  as  has  been 
already  observed,  proceeds  downwards,  and  fre- 
quently adheres  to  the  crural  nerve,  for  a short  dis- 
tance, near  Poupart’s  ligament,  but  soon  leaves  it, 
and  descends  on  the  inside  of  the  thigh,  supplying 
the  integuments  as  low  as  the  knee. 

THE  OBTURATOR  NERVE 

Descends  into  the  pelvis,  and  passes  out  of  it  at  the 
upper  part  of  the  foramen  thyroideum  ; proceeding 
downwards  in  an  internal  direction,  to  be  distributed 
on  the  inside  of  the  thigh. 

This  nerve  is  generally  accompanied  by  the  obtu- 
rator artery  and  vein  ; the  artery  being  above,  and 
the  vein  below  it.  When  it  has  arrived  at  the  fora- 
men ovale  or  thyroideum,  it  sends  off  a branch  to 
the  internal  and  external  obturator  muscles,  and, 
after  passing  these  muscles,  divides  into  two  branches 
which  are  distributed  to  the  muscles  on  the  inside  of 
the  thighs,  the  adductors,  the  pectineus,  the  graci- 
lis, &c. 

THE  CRURAL  NERVE 

Is  situated  at  first  behind,  and  then  on  the  outside  of 
the  psoas  muscle.  It  passes  under  Poupart’s  liga- 
ment with  the  great  femoral  vessels,  being  on  the 
outside  of  the  artery. 

It  is  distributed  to  the  integuments,  and  also  to 
the  muscles,  which  are  situated  on  the  anterior  and 
internal  parts  of  the  thigh.  Some  of  its  ramifications 
go  off  before  it  passes  under  Poupart’s  ligament* 


336  Crural  Nerve. — Sacral  Nerves. 

Several  of  them  are  spent  upon  the  integuments,  and 
are  therefore  denominated  Cutaneas. — They  are 
distinguished  by  the  terms  Cutaneus  Anterior , Cu- 
taneous Interims,  &c.  according  to  their  situations. 

The  deep-seated  branches  are  the  largest.  They 
are  principally  spent  upon  the  muscles  on  the  ante- 
rior and  the  internal  side  of  the  thigh,  viz.  the  four 
extensors,  the  adductors,  the  pectineus,  the  sar  tori  us, 
and  the  gracilis.  Among  these  nerves  there  is  one, 
called  the  Saphenus,  which  has  a different  destina- 
tion. It  accompanies  the  great  artery  of  the  thigh  to 
the  place  where  it  perforates  the  Adductors  : it  there 
separates  from  the  artery,  and  passes  over  the  tendon 
of  the  Adductors,  under  the  sartorius  muscle ; thence 
it  continues,  with  the  great  saphena  vein,  on  the  in- 
side of  the  leg,  to  the  internal  ankle ; sending  branches 
to  the  integument,  in  its  course.  It  terminates  in  skin 
and  cellular  substance  on  the  upper  and  internal  sur- 
face of  the  foot. 

The  SACRAL  Nerves 

Are  composed  of  those  cords  of  the  cauda  equina, 
which  remain  after  the  formation  of  the  lumbar 
nerves.  They  are  frequently  stated  to  consist  of 
five  or  six  pair,  four  of  which  pass  through  the  fo- 
ramina of  the  sacrum,  and  the  fifth  between  the  sa- 
crum and  the  os  coccygis.*  The  cords  of  which 
they  are  respectively  composed  arise  by  anterior  and 
posterior  fasciculi.  When  they  have  arrived  oppo- 
site to  the  foramina  of  the  sacrum,  through  which  they 
are  to  pass,  a ganglion  is  formed,  at  which  they 
unite,  and  then  divide  into  anterior  and  posterior 
branches.!  The  uppermost  of  the  anterior  branches 

* The  sixth  pair,  when  they  exist,  ’proceed  in  a groove  in  the  os 
coccygis. 

t The  ganglions  of  the  fourth  and  fifth  nerves  are  extremely  small  and 
not  so  near  the  foramina  as  those  of  the  others. 


Sciatic  Plexus.—  Pudic  Nerve.  337 

are  large  and  pass  through  the  anterior  foramina  of 
the  sacrum.  The  posterior  are  small,  and  go  through 
the  posterior  foramina. 

The  Posterior  branches  are  generally  spent  upon 
the  muscles  which  lie  on  the  sacrum,  and  posterior 
parts  of  the  pelvis,  externally. 

The  anterior  branches  of  the.  three  first  nerves 
send  ramifications  to  the  sympathetic.  They  unite  to 
each  other,  and  are  joined  by  the  last  lumbar  nerve, 
and  by  a branch  of  the  fourth  sacral,  in  the  forma- 
tion of  the  great  sciatic  nerve.  This  union  constitutes 
the  Sciatic  plexus. 

The  anterior  branch  of  the  fourth  nerve  transmits 
branches  to  the  sympathetic:  it  also  sometimes  sends 
a branch  to  the  united  nerves  above,  or  the  sciatic 
plexus.  It  sends  branches  to  the  hypogastric  plexus, 
and  to  the  contiguous  muscles. 

The  fifth  and  sixth  pairs,  which  are  very  small, 
terminate  also  in  the  contiguous  muscles  and  in  the 
integuments. 

From  the  Sciatic  plexus , or  the  nerves  which  com- 
pose it,  several  smaller  branches  go  off.  There  are 
generally  two  which  pass  off  backwards  through  the 
ischiatic  notch,  and  are  denominated  Gluteal,  as  they 
are  distributed  to  the  glutei  muscles.  From  the  low- 
ermost of  these  a branch  descends  on  the  thigh. 

The  Pudic  nerve,  which  is  appropriated  to  the  or- 
gans of  generation,  also  passes  off  from  this  plexus, 
and  appears  to  consist  of  fibres  which  are  derived 
from  each  of  the  nerves  that  compose  it.  It  proceeds 
between  the  sacrosciatic  ligaments,  and  divides  into 
two  branches — an  inferior  and  a superior.  The  in- 
ferior passes  between  the  erector  penis  and  the  ac- 
celerator urinse  muscles,  and  is  distributed  to  those 
muscles,  to  the  bulb  of  the  urethra  and  the  interior 
of  that  canal,  to  the  scrotum  and  dartos. 

The  superior  proceeds  along  the  os  pubis  to  the 


U5&  Course  of  the  Great  Sciatic  Nerve. 

symphisis,  and  passes  between  the  bone  and  the  body 
of  the  penis  to  the  dorsum.  A considerable  branch 
accompanies  the  artery  on  the  dorsum,  and  terminates, 
by  many  ramifications,  on  the  glans  penis;  after  send- 
ing branches  in  its  course  to  the  integuments  gene- 
rally, and  to  the  prepuce. 

In  females,  the  Inferior  pudic  nerve  proceeds  along 
the  external  labia  pudendi  to  the  mons  veneris,  send- 
ing off  many  ramifications  in  its  course. 

The  Superior  pudic  nerve  proceeds,  as  in  males, 
along  the  branch  of  the  pubis  to  the  superior  surface 
of  the  clitoris,  and  terminates  principally  upon  the 
extremity  of  that  organ. 

The  sacral  nerves  unite  in  the  sciatic  plexus  to 
form  the  great  nerve  of  the  lower  extremity,  which 
is  next  to  be  described. 

The  GREAT  SCIATIC  JYerve 

Proceeds  from  the  pelvis  through  the  ischiatic  notch, 
between  the  pyramidalis  and  the  superior  gemellus 
muscle : it  then  passes  down  to  the  back  part  of  the 
thigh,  between  the  tuberosity  of  the  ischium  and  the 
great  trochanter  of  the  os  femoris ; and  continues 
downwards,  inclining  from  within  outwards,  to  the 
ham,  where  it  is  situated  between  the  tendons  of  the 
semi-tendinosus  and  semi-membranosus  on  the  inter- 
nal side,  and  the  tendon  of  the  biceps  on  the  external. 
In  this  course  it  sends  off  branches  to  the  muscles  on 
the  posterior  part  of  the  thigh. 

As  the  great  nerve  passes  down  the  thigh,  it  sends 
off  obliquely  downwards  and  outwards,  a large 
branch  which  is  called  the  Fihular , that  passes 
across  the  head  of  the  fibula  to  the  external  and 
anterior  part  of  the  leg.  The  place  where  this 
branch  separates  from  the  main  nerve  is  different  in 
different  subjects.  It  continues  in  contact  with  it 


Distribution  of  the  Fibular  Nerve » 359 

for  some  distance,  connected  only  by  cellular  mem- 
brane. 

THE  FIBULAE  Oil  PERONEAL  NERVE 

Proceeds  downwards  on  the  inside  of  the  tendon  of 
the  biceps,  and  crosses  obliquely  to  the  outside  of  the 
external  head  of  the  gastrocnemius:  it  then  passes 
inwards  between  the  long  peroneus  muscle  and  the 
fibula;  and  descending  between  the  muscles  on  the 
front  of  the  leg,  divides  into  two  branches,  one  of 
which  inclines  to  the  exterior  side  of  the  leg,  and 
the  other  preserves  an  internal  situation.  In  its  course 
from  the  great  sciatic  nerve  to  the  fibula,  it  sends  off 
some  superficial  ramifications.  The  two  branches 
into  which  it  divides,  after  passing  over  the  fibula, 
continue  downwards.  The  Internal , after  supply- 
ing the  muscles  on  the  anterior  part  of  the  leg, 
passes  under  the  annular  ligament  like  the  anterior 
tibial  artery;  and  on  the  upper  part  of  the  foot,  di- 
vides into  two  ramifications,  one  of  which  proceeds 
forwards  near  the  internal  edge  of  the  foot,  and  the 
other  near  the  external ; they  divide  again,  and  are 
distributed  to  the  parts  on  the  upper  surface  of  the 
foot,  one  of  their  ramuli  descending  with  the  conti- 
nuation of  the  anterior  tibial  artery  to  the  sole  of  the 
foot. 

The  External  Branch  of  the  fibular  nerve,  as  it 
proceeds  downwards,  supplies  ramifications  to  the 
contiguous  muscles,  and  passing  through  the  fascia 
on  the  outside  of  the  leg,  continues  between  it  and 
the  skin  towards  the  foot.  In  this  course  it  gene- 
rally divides  into  two  branches  which  are  spent  upon 
the  upper  surface  of  the  foot. 

The  GREAT  SCIATIC  Nerve , after  the  fibular 
nerve  leaves  it,  continues  down  the  thigh,  between 
the  tendons  of  the  flexors,  behind  the  great  blood 
vessels,  and  of  course  exterior  to  them. 


360  Distribution  of  the  Tibial  Nerve. 

In  the  ham,  this  great  nerve  takes  the  name  of 
POPLITEAL,  and  proceeds  across  the  articulation 
of  the  knee,  between  the  heads  of  the  gastrocnemii, 
to  the  posterior  side  of  the  tibia  : here  it  passes 
through  the  upper  portion  of  the  soleus  or  gastroc- 
nemius internus,  and  continues  between  it  and  the 
long  flexor  of  the  toes,  near  the  Posterior  Tibial  Ar- 
tery ; descending  with  that  artery  to  the  hollow  of  the 
os  calcis.  In  this  situation  it  has  the  name  of 

POSTERIOR  TIBIAL  NERVE. 

At  the  commencement  of  this  course,  a small  dis- 
tance below  the  internal  condyle  of  the  os  femoris, 
it  sends  off  a branch  of  considerable  size  called  the 
Communieans  Tibas,  or  Saphena  Externa,  which 
passes  down  behind  the  gastrocnemii,  and  gradually 
inclines  externally,  so  that  it  is  situated  on  the  ex- 
ternal edge  of  the  tendo  Achillis,  soon  after  the  com- 
mencement of  that  tendon,  and  proceeds  behind  the 
external  ankle,  near  the  outer  side  of  the  foot,  to  the 
smaller  toes:  distributing  branches  to  the  contiguous 
parts.  In  its  course  on  the  back  of  the  leg,  it  sends 
off  a branch  which  unites  with  one  of  the  superficial 
ramifications  of  the  fibular  nerve,  and  descends  to  the 
outer  part  of  the  foot. 

The  Tibial  Nerve,  in  its  course  downwards,  sends 
branches  to  the  contiguous  muscles ; and  a few  twigs 
which  form  a species  of  net-work  on  the  artery.  In 
the  hollow  of  the  os  calcis  it  sends  off  a superficial 
branch  to  the  integuments  of  the  sole  of  the  foot, 
which  proceeds  on  the  outside  of  the  aponeurosis 
plantaris:  it  there  also  divides  into  branches,  which 
are  denominated  the  Internal  and  External  Plantar 
Nerves. 

The  Internal  Plantar  Nerve  proceeds  forwards, 
along  side  of  the  tendon  of  the  long  flexor  muscle  of 
the  great  toe,  givin'g  off  small  branches  in  its  course. 


Commencement  of  the  Sympathetic  Nerve,  361 

About  the  middle  of  the  foot  it  divides  into  four 
branches,  one  of  which  proceeds  to  the  inside  of  the 
great  toe ; and  a second  to  the  angle  formed  by  thb 
great  toe  and  the  toe  next  to  it,  where  it  divides  and 
sends  a branch  to  the  opposite  sides  of  those  toes : 
the  other  two  branches  are  distributed  in  a similar 
manner,  to  the  succeeding  toes.  These  digital  branches 
are  connected  with  each  other  by  small  ramifications. 

The  External  Plantar  Nerve  proceeds  with  the 
external  plantar  artery  towards  the  externel  side  of 
the  foot,  between  the  short  flexor  of  the  toes  and  the 
flexor  accessorius.  Near  the  external  edge  of  the 
foot,  about  the  posterior  end  of  the  metacarpal  bones, 
it  divides  into  three  branches.  One  proceeds  to  thd 
outside  of  the  little  toe;  another  passes  to  the  angle 
between  the  fourth  toe  and  the  little  toe,  and  divides 
into  branches  which  are  distributed  to  the  correspond- 
ing sides  of  these  toes.  The  third  branch  proceeds 
more  deeply  in  the  foot,  from  the  external  towards 
the  internal  edge  of  it,  and  is  spent  upon  the  deep- 
seated  contiguous  muscles. 

THE  GREAT  SYMPATHETIC  OR  INTERCOSTAL  NERVE 

Commences  in  the  cranium  with  those  small  ramifica- 
tions of  the  pterygoid  branch  of  the  upper  maxillary 
nerve,  and  of  the  sixth  pair,  which  accompany  the 
carotid  artery  through  the  canal  in  the  petrous  portion 
of  the  temporal  bone.  These  small  nerves  from  a 
net-work  which  surrounds  the  artery  in  the  canal,  and 
gives  rise  to  the  incipient  sympathetic,  a small  cord 
which  passes  down  close-  to  the  nerves  of  the  eighth 
and  ninth  pair  of  the  neck.  Opposite  to  the  second 
cervical  vertebra,  this  nerve  is  swelled  or  dilated,  so 
as  to  form  a body  of  a light  red  colour,,  which  is  more 
than  an  inch  in  length,  and  has  the  form  of  two  cones 
united  to  each  other  at  their  bases.  This  is  the  Su- 
perior Cervical  Ganglion  of  the  Sympathetic  Nerve* 
Vol.  ii,  ^46  " 


362  First  Ganglion,  and  other  Cervical 

and  from  it  tlie  nerve  descends?  behind  the  Par  Va- 
guin, on  the  front  part  of  the  neck. 

This  ganglion  receives  twigs  from  the  first,  second, 
third  and  fourth  pairs  of  cervical  nerves,  and  also  from 
the  eighth  and  ninth  nerves  of  the  head.  It  sends  off 
several  twigs,  which  pass  behind  the  carotid  artery, 
at  its  bifurcation,  and  are  joined  by  twigs  of  the  Por- 
tio  Dura  and  the  Glosso- Pharyngeal  nerves.  From 
these  united  twigs  proceed  very  small  ramifications, 
which  accompany  several  branches  of  the  external 
carotid  artery,  and  some  of  them  pass  down  with  the 
Common  Carotid. 

This  superior  ganglion  also  furnishes  small  twigs 
which  accompany  theGlosso-Pharnygeaho  the  tongue 
and  pharynx.  Sometimes  a twig  from  it  passes  on 
the  back  part  of  the  thyroid  gland  to  communicate 
with  the  recurrent  nerve.  From  this  ganglion  go 
off  some  small  branches,  which,  uniting  with  others 
from  the  superior  laryngeal  nerves,  form  the  supe- 
rior or  superficial  cardiac  nerve,  which  will  be  soon 
described. 

The  trunk  of  the  Sympathetic  Nerve  descends,  on 
the  front  of  the  neck,  front  this  ganglion,  as  has  been 
already  stated.  In  its  course  it  receives  very  small 
twigs  from  the  fourth  and  fifth  cervical  nerves,  and 
sends  some  very  small  twigs  which  appear  to  go 
to  the  oesophagus,  and  some  which  unite  to  the  la- 
ryngeal nerve  and  go  to  the  thyroid  gland.  Some 
twigs,  which  are  larger,  proceed  from  it  into  the 
thorax,  and  go  to  the  cardiac  plexus  hereafter  to  be 
described. 

Opposite  to  the  interval  between  the  fifth  and 
sixth  cervical  vertebrae  it  forms  another  ganglion,  of 
an  irregular  shape,  much  smaller  than  the  first.  This 
ganglion,  in  different  subjects,  differs  in  size  as  well 
as  in  several  other  respects.  Sometimes  it  is  en- 
tirely wanting,  and  sometimes  it  is  doubled.  It  is 


Ganglions  and  Branches  of  the  Sympathetic.  363 

denominated  the  Middle  Cervical , or  Thyroid  Gan- 
glion. When  the  fourth,  fifth,  and  sixth  cervical 
nerves  do  not  send  ramifications  to  the  sympathetic 
nerve,  this  ganglion  receives  twigs  from  them. 

The  Middle  Cervical , or  Thyroid  Ganglion  sends 
many  ramifications  downwards.  Some  of  them  enter 
the  thorax  and  contribute  to  the  formation  of  the 
Cardiac  Plexus ,*  others  accompany  the  inferior 
thyroid  artery,  and,  with  twigs  from  the  recurrent 
nerve,  form  a plexus  which  extends  towards  the 
thyroid  gland.  Some  proceed  downwards  before, 
and  others  behind,  the  subclavian  artery,  to  the  next 
ganglion ; and  among  them  is  generally  one  which 
may  be  regarded  as  the  trunk  of  the  Sympathetic. 

This  third  Ganglion  is  denominated  the  Inferior. 
Cervical , or  the  First  Thoracic.  It  is  almost  con- 
stantly found  in  the  same  situation,  viz.  between  the 
transverse  process  of  the  last  cervical  vertebra  and 
the  head  of  the  first  rib,  and  is  partly  covered  by  the 
origin  of  the  vertebral  artery.  It  is  generally  larger* 
than  the  middle  ganglion.  It  receives  branches  from 
the  sixth  and  seventh  cervical,  and  the  two  first  dor- 
sal nerves.  Ramifications  pass  from  it  to  the  par  va- 
gum  and  recurrent  nerve,  and  also  to  the  cardiac  and 
pulmonary  plexus. 

From  this  ganglion  the  Sympathetic  Nerve  pro- 
ceeds  downwards  on  the  side  of  the  spine,  as  will  be 
described  hereafter. 

The  Nerves  of  the  Heart , 

Being  derived  from  branches  which  have  already  been 
mentioned,  are  now  to  be  described. 

They  arise  principally  from  an  arrangement  of 
nerves  denominated  the  Cardiac  Plexus , or  Plex- 
uses, which  is  situated  above  the  curve  of  the  aorta, 
and  extends,  on  the  posterior  side  of  it,  from  the 
root  of  the  arteria  imiominata  to  the  bifurcation  of 


i 


>64  Branches  of  the  Sympathetic . 

the  pulmonary  artery.  This  plexus  is  composed  of 
nerves  which  are  principally  formed  by  the  union 
of  small  ramifications  that  are  derived  from  the  three 
above  mentioned  ganglions  of  the  Sympathetic  Nerve , 
and  the  nerve  itself ; and  also  from  the  Par  Vagum 
and  some  of  its  branches* 

These  nerves  are  denominated  the  Cardiac. — - 
They  descend  on  their  respective  sides  of  the  neck, 
but  are  somewhat  different  on  the  different  sides. — 
On  the  right  side  three  nerves  have  been  described 
as  particularly  entitled  to  this  name,  and  on  the  left 
side  but  two. 

The  first  on  the  right  side  is  denominated  Supe- 
rior, or  Superficial  Cardiac  NeiPve . It  generally 
arises  by  several  fine  threads,  which  unite  into  one 
delicate  cord  that  passes  down  by  the  side  of  the 
common  carotid.  When  it  has  arrived  on  a line 
with  the  middle  ganglion,  it  sends  a twig  to  the  thy- 
roid plexus,  and  another  that  communicates  with  a 
twig  from  the  par  vagum,  which  continues  downwards 
on  the  carotid  artery.  After  passing  beyond  the  gan- 
glion, it  divides  into  several  branches,  which  unite 
themselves  to  branches  of  the  recurrent  nerve  that 
are  going  to  the  middle  ganglion. 

The  second,  which  is  denominated  the  Middle 
Cardiac , the  Great  Cardiac,  or  the  Deep  Cardiac , 
is  the  largest  of  the  three.  It  arises  from  the  Mid- 
dle Cervical,  or  Thyroid  Ganglion,  by  five  or  six 
fine  fibrils,  which  finally  form  one,  that  passes  before 
and  across  the  subclavian;  and  at  that  place  as  well 
as  lower  down,  it  receives  twigs  from  the  par  vagum : 
below  this,  it  is  joined  by  a considerable  twig  from 
the  recurrent,  and  terminates  in  the  Cardiac  Plexus , 
to  which  it  contributes  largely. 

The  third  cardiac  nerve  of  the  right  side  is  called 
the  Inferior,  or  the  Small  Cardiac  Nerve.  It  ori- 
ginates from  the  third,  or  lower  cervical  ganglion,  by 


365 


Branches  of  the  Sympathetic . 

many  fibrils  which  unite  into  a smaller  number  that 
form  a plexus.  It  crosses  behind  the  subclavian, 
and  proceeds  on  the  outside  of  the  Arteria  Irmomi- 
nata  to  the  curve  of  the  aorta ; continuing  between 
it  and  the  pulmonary  artery,  to  the  anterior  corona- 
ry  plexus.  In  this  course  it  receives  several  fibres 
from  the  recurrent  and  the  par  vagum. 

On  the  left  side  the  first  cardiac  nerve  arises  from 
the  upper  ganglion.  The  second  derives  its  origin 
from  the  two  lower  ganglions. 

The  left  superior  or  superficial  cardiac  nerve  arises 
like  the  right,  by  many  distinct  fibres,  and  proceeds 
downwards  in  the  same  way.  It  descends  betweed 
the  carotid  and  the  subclavian,  and  when  it  has  ar- 
rived at  the  place  where  they  originate  from  the  aorta, 
it  divides  into  a great  number  of  small  ramifications. 
Some  pass  before  the  aorta,  either  to  join  the  branches 
of  the  inferior  cardiac,  or  to  unite  with  the  cardiac 
branches  of  the  left  nerve  of  the  par  vagum.  The 
others  proceed  behind  the  aorta,  and  enter  into  the 
common  cardiac  plexus. 

The  second  cardiac  nerve  of  the  left  side  may  be 
called  the  Great  Left  Cardiac,  and  has  a double 
origin  as  above  mentioned.  The  principal  branch 
in  its  composition  arises  from  the  lowest  cervical 
ganglion,  and  passes  behind  the  transverse  portion 
of  the  subclavian  artery.  , Where  the  inferior  thyroid 
arises  from  the  subclavian,  this  branch  receives  a 
considerable  number  of  ramifications,  which  arise 
from  the  upper  ganglion,  and  are  interwoven  with 
each  other  before  they  unite  to  it.  It  passes  behind 
the  curve  of  the  aorta,  and  terminates  in  the  great 
cardiac  plexus,  which  it  particularly  contributes  to 
form.  Here  it  is  joined  by  many  fibres  from  the 
par  vagum.  • 


366  Plexus  formed  by  the  Nerves  of  the  Heart . 

The  Cardiac  Plexus 

Is  situated  principally  behind  the  curve  of  the  aorta, 
at  a small  distance  above  the  heart.  It  commences 
as  high  as  the  origin  of  the  Arteria  Innominata,  and 
extends  downwards  to  the  bifurcation  of  the  pulmo- 
nary artery. 

As  has  been  already  mentioned,  it  is  principally 
composed  of  branches  from  the  middle  cardiac  nerve 
of  the  right  side,,  and  the  inferior  cardiac  nerve  of 
the  left ; but  it  receives  branches  from  the  superior 
cardiac  of  the  left,  and  sometimes  of  the  right  side. 
Some  fibres  of  the  inferior  cardiac  of  the  right  are 
also  united  to  it. 

Many  branches  proceed  from  this  plexus. 

A small  number  pass  upon  the  aorta,  and  seem  to 
enter  into  its  texture.* 

Some  of  them  also  combine  with  the  ramifications 
of  the  Par  Vagum  in  the  anterior  pulmonary  plexus. 

The  majority  proceed  to  the  basis  of  the  heart, 
near  the  origin  of  the  pulmonary  artery  and  the  aorta, 
and  constitute  the  proper  nerves  of  that  organ . They 
accompany  the  coronary  arteries,  and  are  so  arranged 
around  them  that,  by  some  anatomists,  they  have 
been  said  to  form  plexuses,  which  have  been  deno- 
minated Coronary. 

The  Sympathetic  Nerve,  as  has  been  stated  above, 
proceeds  from  the  ganglion,  called  the  Lower  Cer- 
vical, or  the  First  Thoracic,  before  the  neck  of  the 
first  rib.  It  continues  to  descend,  in  the  same  direc- 
tion, along  the  spine,  exterior  to  the  pleura,  to  the  infe- 
rior part  of  the  thorax.  Near  the  head  of  each  rib  it 
forms  a ganglion,  which  unites  with  the  intercostal 
nerve  behind  it,  by  two  branches,  and  thus  forms  an 
indirect  communication  with  the  medula  spinalis. 


* It  has  been  asserted,  that  some  of  the  anatomists  of  Paris  have  traced 
tbese.nerves  on  the  aorta,  to  a great  distance  from  the  heart. 


Sympathetic  Nerve,  fyits  Splanchnic  Branches.  367 

From  several  of  the  uppermost  of  these  ganglions, 
small  twigs  proceed  to  the  pulmonary  plexus,  and 
also  to  the  great  trunk  of  the  aorta,  below  the  curve, 
forming  a species  of  net-work,  or  plexus,  upon  it. 

From  the  ganglions  near  the  heads  of  the  fifth  and 
sixth  ribs,  and  from  four  or  five  of  the  ganglions 
tfhich  succeed  them,  small  nerves  arise,  which  pro- 
ceed downwards  on  the  sides  of  the  bodies  of  the 
vertebrae,  and  unite  into  one  trunk  that  is  denomi- 
nated the  Splanchnic  Nerve,  because  it  is  distributed 
to  the  viscera  of  the  abdomen. — This  nerve  proceeds 
behind  the  crus  of  the  diaphragm,  on  its  respective 
side,  into  the  abdomen.  A second  and  smaller  nerve, 
of  the  same  destination,  called  the  Lesser  Splanchnic 
Nerve,  arises  lower  down,  from  two  or  three  of  the 
lowermost  dorsal  ganglions,  and  penetrates  separate- 
ly into  the  cavity  of  the  abdomen  : it  then  generally 
divides  into  two  branches,  one  of  which  unites  to  the 
great  splanchnic  nerve,  and  the  other  proceeds  to  the 
renal  plexus  soon  to  be  described. 

As  soon  as  the  great  splanchnic  nerve  has  entered 
the  abdomen,  it  divides  into  many  branches,  which 
commonly  form  small  ganglions  on  each  side  of  the 
c celiac  artery,  but  above  it.  • These  ganglions  are 
generally  contiguous  ; but  sometimes  they  are  at  a 
small  distance  from  each  other,  and  united  by  nerves. 
They  are,  however,  commonly  spoken  of  as  one,  and 
called  the  Semilunar  Ganglion.  They  are  of  ir- 
regular forms,  and  very  different  from  each  other  in 
size,  as  well  as  form.  Those  formed  by  the  splanch- 
nic nerve  on  one  side  are  sometimes  different  from 
those  on  the  other. 

From  this  assemblage  of  ganglions  proceed  many 
small  nerves,  which  are  woven  together  so  as  to  form 
a net-work  denominated  the  Solar  Plexus. 

This  plexus  is  situated  anterior  to  the  spine  and 
the  crura  of  the  diaphragm  ; behind  the  stomach  and 


368  Arrangement  of  the  Nerves  of  the 

above  the  pancreas ; and  is  extended  upon  the  coeliae 
arid  superior  mesenteric  arteries.  Some  ramifications 
from  the  par  vagum  and  the  phrenic  also  join  it. 

The  lower  part  of  the  solar  plexus,  which  sur- 
rounds more  immediately  the  coeliae  artery,  is  termed 
the  Coeliae  Plexus.  From  it  net-works  of  nerves  ex- 
tend upon  the  great  branches  of  the  artery  to  the 
organs  which  they  go  to. 

They  extend  to  the  stomach,  (although  it  is  sup- 
plied by  the  par  vagum,)  along  the  superior  coronary 
or  gastric  branch  of  the  coeiiac ; and  the  fibres  in  their 
composition  being  spread  upon  the  coats  of  the  sto- 
mach, unite  with  the  branches  of  the  par  vagum, 
which  are  also  spread  upon  them. 

A similar  net- work,  denominated  the  Hepatic 
Plexus , extends  upon  the  Hepatic  Artery , and  from 
it  to  the  Vena  Portarum ,*  and  accompanies  those 
vessels  into  the  substance  of  the  liver.  It  also  sends 
branches  to  the  biliary  duct  and  gall  bladder  ; to  the 
stomach  by  the  arteria  gastrica  dextra  ; and  to  the 
omentum. 

The  Sple?iic  Artery  is  invested  by  a similar  but 
smaller  arrangement  of  nerves,  denominated  the 
Splenic  Plexus.  In  its  course  .to  the  spleen,  this 
plexus  sends  some  nerves  to  the  pancreas  ; and  also 
to  the  stomach  and  omentum,  with  the  left  gastric 
artery. 

The  superior  mesenteric  artery  is  surrounded  by  a 
net-work,  which  extends  to  it  directly  from  the  solar 
plexus,  and  is  the  largest  of  all  which  proceed  from 
that  plexus.  The  Mesenteric  Plexus  at  first  nearly 
surrounds  the  artery,  and  proceeds  with  it  between 
the  lamina  of  the  mesentery.  In  this  course  it  sends 
branches,  with  the  arteria  dolica  dextra,  to  the  trans- 
verse portion  of  the  colon.  Between  the  lamina  of 
the  mesentery,  it  sends  ramifications  with  all  the 
branches  of  the  artery,  to  the  small  intestines  gene- 


Abdominal  Viscera „ 


369 


rally;  to  the  ececum,  and  the  right  portion  of  the 
colon ; as  well  as  to  the  mesenteric  glands. 

From  the  lower  part  of  the  solar  plexus  a net-work 
proceeds,  on  the  front  of  the  aorta,  to  the  inferior 
mesenteric  artery,  and  surrounds  it.  Nerves  from 
this  plexus  accompany  the  artery  to  the  left  portion 
of  the  colon  and  the  rectum.  Some  of  their  ramifi- 
cations combine  with  those  of  the  hypogastric  plexus. 

The  Emulgent  Artery  is  attended  by  nerves,  which 
are  arranged  like  a net-work  on  its  anterior  and  poste- 
rior surfaces,  and  are  denominated  the  Renal  Plexus . 
They  are  derived  from  the  solar  plexus,  and  fre- 
quently contain  small  ganglions.  They  proceed 
with  the  artery  to  the  fissure  of  the  kidney,  and  are 
distributed  with  its  different  ramifications,  in  the 
substance  of  the  organ. 

Some  branches  pass  from  them  to  the  renal  gland 
with  the  capsular  artery. 

Before  the  renal  plexus  arrives  at  the  kidney,  it 
sends  off,  from  its  inferior  part,  some  new  fibres, 
which,  after  joining  some  others  from  one  of  the 
lumbar  nerves,  accompany  the  spermatic  arteries,  and 
are,  therefore,  called  the  Spermatic  Plexus.  In  the 
male  these  fibres  proceed  through  the  abdominal 
ring,  and  many  of  them  go  to  the  testis,  but  they 
are  followed  with  great  difficulty,  on  account  of  their 
small  size. 

In  the  female,  they  go  to  the  ovary  and  the  fallo- 
pian tube. 

From  the  great  plexuses  above,  a small  net-wTork 
continues  downwards  on  the  aorta,  receiving  fibres 
from  the  intercostals  on  each  side  ; at  the  great  bifur- 
cation of  the  aorta  it  divides,  and  is  joined  on  each 
side  by  many  ramifications  from  the  third  lumbar 
nerves,  which  thus  form  a plexus  of  considerable 
extent,  that  sends  nerves  to  the  bladder,  rectum,  and 
vesiculse  seminales  in  males;  and  to  the  uterus  and 

Yol,  ii.  47 


370  Termination  of  the  Sympathetic  Nerve, 

vagina,  as  well  as  the  bladder  and  rectum,  in  fe- 
males.* This  is  called  the  Hypogastric  Plexus . 

The  plexuses  above  mentioned  are  derived  from 
the  splanchnic  nerve,  which  came  off  from  the  Sym- 
pathetic in  the  thorax. 

The  Sympathetic  Nerve,  after  giving  off  the  lesser 
splanchnic^  is  diminished  in  size,  and  approaches 
nearer  to  the  bodies  of  the  vertebra.  It  passes 
through  the  crura  of  the  diaphragm,  and  then  pro- 
ceeds forwards  and  downwards  upon  the  spine,  be- 
tween the  tendinous  crura  of  the  diaphragm  and 
psoas  muscle ; near  the  vena  cava  on  the  right  side, 
and  the  aorta  on  the  left.  In  this  course,  it  gene- 
rally receives  one  or  two  small  cords  from  the  ante- 
rior branch  of  each  of  the  lumbar  nerves:  these  cords 
proceed  downwards  and  forwards,  between  the  bo- 
dies of  the  vertebrae  and  the  psoas  muscle,  and  a 
ganglion  is  generally  formed  at  the  plaee  where  they 
join  the  nerve. 

In  its  descent  on  the  lumbar  vertebrae,  the  Sym- 
pathetic sends  off  several  nerves  that  unite  to  the 
net-work  nvhich  descends  on  the  aorta  from  the  plexus 
above.  After  passing  over  the  lumbar  vertebrae,  it 
descends  into  the  pelvis,  close  to  the  sacrum,  on  the 
inner  side  of  the  great  foramina:  here  it  also  forms 
ganglions,  and  communicates  with  the  sacral  nerves, 
and  likewise  with  the  hypogastric  plexus.  It  termi- 
nates on  the  os  coccygis,  where  its  minute  fibres  join 
those  of  the  opposite  side. 

* Although  the  testicle  receives  nerves  which  are  derived  from  the  Sym* 
pathetic,  the  penis  and  other  external  parts  of  the  organs  of  generation  do 
not:  the  nerves  which  accompany  the  pudic  artery  being  derived  from  those 
which  unite  to  form  the  great  Sciatic, 


SYSTEM  of  anatomy. 


PART  XI. 


OF  THE  ABSORBENT  VESSELS.* 

The  absorbent  vessels  are  small  transparent  tubes, 
of  a delicate  structure,  which  exist  in  considerable 
numbers  in  almost  every  part  of  the  body. 

These  tubes  originate  upon  the  surfaces  of  all  the 
cavities  of  the  body;  and  of  the  cellular  membrane, 
in  all  the  various  parts  into  which  it  penetrates  ; upon 
the  internal  surface  of  the  stomach  and  the  intes- 
tines ; and  probably  upon  the  skin. 

Those  which  originate  in  the  Lower  Extremities 
and  the  Cavity  of  the  Abdomen,  unite  and  form  a large 
trunk  called  the  Thoracic  Duct , which  proceeds 
through  the  thorax,  and  terminates  in  the  left  Sub- 
clavian Vein,  at  its  junction  with  the  Internal  Jugu- 
lar. Those  of  the  Left  Upper  Extremity,  the  Left 
Side  of  the  Head,  and  the  contiguous  parts,  form  a 
trunk  which  terminates  in  the  same  place.  While 
the  remaining  absorbents,  or  those  of  the  Right  Up- 
per Extremity,  and  the  Right  side  of  the  Head , 
8,'C.  also  form  a trunk,  which  terminates  in  the  cor- 
responding part  of  the  Right  Subclavian  Vein. 

The  absorbent  vessels  of  the  middle  size,  which 

* Discovered  at  Leyden  in  1650..  by  Olaus  Rndbeck.  and  at  Copenhagen 
in  1651.  by  Bartholine. — Ed  ' 


372  Structure  of  the  JibsQrbent  Vessels. 

arise  from  the  union  of  the  small  vessels,  and  unite 
to  form  the  larger,  in  their  progress  to  these  large 
vessels,  pass  through  certain  bodies  which  have  been 
denominated  Conglobate  Glands,  and  may  be  consi- 
dered as  appendages  of  the  absorbent  system. 

The  absorbent  vessels  are  composed  of  two  coats, 
v hich  are  thin,  but  dense  and  firm,  and  also  elastic. 
The  coats  of  the  thoracic  duct  may  be  separated 
from  each  other.  The  internal  surface  of  the  exte- 
rior coat  is  fibrous.  The  internal  coat  is  a delicate 
but  strong  membrane. — There  is  great  reason  to  be- 
lieve that  the  above  mentioned  fibres  are  muscular, 
or  at  least  irritable  : for  the  absorbent  vessels  have 
been  observed,  by  Haller,  to  contract  upon  the  ap- 
plication of  strong  sulphuric  acid.  They  have  also 
been  observed  to  propel  their  contents  with  consider- 
able rapidity,  by  their  own  contraction,  independent 
of  pressure,  or  of  motion  communicated  by  any  other 
body. 

Blood  vessels  are  sometimes  observable  in  the 
coats  of  the  larger  absorbents,  in  injected  subjects. 
The  vascularity  of  these  tubes  may  also  be  inferred 
from  the  inflammation  which  frequently  takes  place 
in  them. 

Nerves  have  not  been  traced  into  their  texture  ; 
but  the  absorbents  seem  to  be  painful  when  they  are 
inflamed,  and,  therefore,  it  is  probable  that  they  are 
supplied  with  nerves. 

The  absorbent  vessels  are  very  generally  supplied 
with  valves,  which  are  much  more  numerous  in  some 
of  them  than  in  others ; and  are  different  in  their 
number,  in  the  same  vessels,  in  different  subjects. 

Very  frequently  there  are  several  valves  in  the 
course  of  an  inch  : sometimes  a valve  will  not  appear 
in  the  course  of  several  inches.  In  the  Thoracic  Duct , 
the  number  of  valves  is  very  different  in  different 
subjects.  These  valves  are  folds  or  plaits  of  the  in- 


Commencement  of  the  Absorbents.  373 

ternal  membrane,  and  are  of  a semi-circular  form. 
There  are  commonly  two  of  them  together  origina- 
ting from  opposite  sides  of  the  vessel. 

The  absorbents  are  generally  somewhat  dilated 
on  the  side  of  the  valve  which  is  next  to  their  termi- 
nation, and  this  occasions  their  knotted  appearance 
when  they  are  injected.  The  object  of  this  valvular 
structure  seems  to  be  the  prevention  of  retrograde 
motion  of  the  contained  fluid,  in  consequence  of  la- 
teral pressure.  • 

• Where  the  different  trunks  of  the  absorbents  open 
into  the  veins,  there  are  one  or  two  valves  to  prevent 
the  regurgitation  of  the  blood  into  them. 

The  valves  of  course  prevent  the  injection  of  the 
branches  of  these  vessels  from  their  trunks. —In  some 
animals  the  valves  have  sometimes  been  ruptured,  or 
forced  back;  and  the  absorbents  have  been  injected 
in  a retrograde  direction.  There  are  but  two  or 
three  instances  upon  record  where  this  has  been 
practicable  in  the  Human  Subject. 

In  consequence  of  the  impracticability  of  injecting 
the  small  branches  from  the  larger,  the  absorbent 
vessels  cannot,  generally,  be  demonstrated  at  their 
commencement,  or  origin.  It  is,  however,  to  be  ob- 
served, that  the  Lacteals , or  Absorbents  of  the  Intes- 
tines, appear  no  way  different  from  other  absorbents; 
and  they  have  been  seen  distended  with  chyle,  from 
their  commencement,  in  certain  subjects  w’ho  had 
died  suddenly.  Their  origins  have  been  described 
very  differently  by  different  observers. 

Mr.  Cruikshank  describes  them  as  originating  on 
the  surfaces  of  the  villi,  by  a number  of  very  small 
radiated  branches  with  open  orifices;  which  branches 
soon  unite  to  form  a trunk. 

Lieberkuhn  believed  them  to  commence  in  the  form 
of  an  ampullula. — See  page  105  of  this  volume. 

The  second  Monro  also  believes  that  the  absorb- 


574  Conglobate  Glands . 

ents  begin  by  very  small  tubes,  with  open  orifices,  in 
several  species  of  fish.* 

It  is  stated  by  Dr.  Soemmering  upon  the  authority 
of  Haase,  a German  anatomist,  that  when  mercury  is 
forced  backwards  in  the  absorbent  vessels  of  tbe  foot 
and  the  heart,  it  has  sometimes  escaped  on  the  sur- 
faces of  those  parts.  The  probable  inference  from 
these  facts  is,  that  those  vessels  originate  by  open 
orifices  on  the  surfaces  of  the  heart  and  foot. 

The  bodies  connected  with  the  absorbent  vessels, 
which  are  called  Conglobate  Glands,  are  generally 
of  a roundish,  or  irregular  oval  form,  and  somewhat 
flattened.  They  are  of  various  sizes,  from  two  lines 
in  diameter  to  more  than  twelve.  Their  colour  is 
frequently  whitish,  but  sometimes  it  is  slightly  in- 
clined to  red.  They  are  invested  with  a covering  of 
cellular  membrane,  which  appears  like  a membranous 
coat ; and  they  are  connected  to  the  contiguous  parts 
by  a loose  cellular  substance.  When  the  absorbent 
vessels  connected  with  these  bodies  approach  near  to 
them,  they  divide  into  a number  of  ramifications, 
most  of  which  enter  into  the  substance  of  the  gland, 
while  some  of  them  run  over  it.  On  the  opposite 
side  of  the  gland  a number  of  branches  go  out,  which 
unite  and  form  trunks  similar  to  those  which  entered 
the  gland.  The  vessels  which  enter  the  gland  are 
called  Vasa  infer entia , and  those  which  go  out  of  it 
Vasa  effer entia. 

These  vessels  are  generally  much  convoluted  in 
the  substance  of  the  glands,  so  that  those  bodies 
sometimes  appear  like  a mere  convolution  of  absorb- 
ent vessels.  There  has  been  much  diversity  of  sen- 
timent respecting  the  structure  of  these  organs.! 

* See  his  work  on  the  Structure  and  Physiology  of  Fishes,  p.  34. 

f Mr.  Abernethy  states,  that  the  mesenteric  gland  of  the  Whale  con- 
sists of  large  spherical  bags  into  which  a number  of  the  lacteals  open. — 
Numerous  blood  vessels  are  ramified  on  the  surfaces  of  these  cysts  ; 


/ 


Fluid  contained  in  the  Absorbents,  375 

The  absorbent  vessels,  in  the  different  parts  of  the 
body,  generally  contain  fluids  resembling  those  which 
are  found  in  those  parts.  Mr.  Hewson  opened  the 
large  absorbents  in  many  living  animals  of  different 
kinds,  and  found  that  they  contained  a transparent 
fluid,  which  coagulated  when  exposed  to  the  air. 

The  arrangement  of  these  vessels  resembles  that 
of  the  veins  in  several  respects.  Many  of  them  are 
superficial ; but  there  are  also  deep-seated  absorbents 
which  accompany  the  blood  vessels. 

and  injection  passes  from  them  into  the  cyst.  He  also  found  cells  in  the 
glands  of  the  absorbent  vessels,  in  the  groin  and  the  axilla  of  the  horse— 
See  Philosophical  Transactions,  for  1796,  Part  I. 


CHAPTER  I. 


OF  THE  ABSORBENTS  OF  THE  LOWER  EXTREMITIES, 
THE  ABDOMEN,  AND  THE  THORAX, 

Under  this  head  are  arranged  the  ramifications  of 
all  the  vessels  which  unite  to  form  the  Thoracic  Duct . 

SECTION  I. 

Of  the  Absorbents  of  the  Lower  Extremities . 

These  absorbents,  like  the  veins,  are  superficial 
and  deep-seated.  The  Superficial  lie  in  the  cellu- 
lar membrane,  very  near  the  skin ; and  form  an  irre- 
gular  net-work  which  extends  over  the  whole  limb. 
They  are,  however,  most  numerous  on  the  internal 
side. 

The  Deep-seated  accompany  the  arteries  like  the 
veins,  and  there  are  two  at  least  to  each  artery. 

The  Superficial  Absorbents 

Have  been  injected  from  the  toes  so  as  to  form  a 
net-work,  which  occupies  the  upper  surface  of  the 
foot.  They  have  also  been  injected  in  a similar 
manner  on  the  sole.  Those  on  the  upper  surface  of 
the  foot  generally  proceed  upward  on  the  anterior 
and  inner  side  of  the  leg;  but  some  of  them  pass  on 
the  external  side  of  it.  Those  on  the  sole  are  con- 
tinued on  the  back  of  the  leg;  but  communicate  very 
frequently  with  the  anterior  vessels.  Some  of  the 
absorbents  from  the  outside  of  the  foot  and  leg  enter 
into  some  of  the  popliteal  glands,  soon  to  be  de- 
scribed; but  they  are  not  numerous;  and  the  princi- 
pal number  continues  up  to  the  glands  of  the  groin. 


Absorbents  of  the  Lower  Extremity.  377 

The  absorbents  which  originate  on  the  surface  of 
the  thigh,  as  we!!  as  those  which  pass  over  it  from 
below,  incline  gradually  a!ong  the  auterior  and  pos- 
terior  surface,  to  the  internal  side  of  it;  on  which 
they  proceed,  in  great  numbers,  and  very  near  to  each 
other,  to  the  inguinal  glands.  Superficial  absorbents 
proceed  also  from  the  buttock,  and  lower  part  of  the 
back,  from  the  lower  part  of  the  abdomen,  the  peri- 
neum and  the  exterior  of  the  genital  organs,  to  these 
glands. 

The  Deep-seated  Absorbents 
Are  named  from  the  arteries  they  accompany. 

The  Anterior  Tibial  Absorbents. 

The  anterior  tibial  artery  is  generally  attended  by 
one  which  comes  with  it  from  the  sole,  and  by  another 
which  commences  on  the  upper  surface  of  the  foot. 
The  first  mentioned  absorbent  continues  with  the  ar- 
tery. The  last  often  passes  through  an  aperture  in 
the  interosseal  ligament,  about  one-third  of  the  dis- 
tance from  the  ankle  to  the  knee,  and  accompanies  the 
fibular  artery,  while  the  anterior  tibial  artery  is  join- 
ed by  other  absorbents  about  the  same  place.  In 
some  instances  a small  absorbent  gland  occurs  in  this 
course,  at  a short  distance  below  the  knee. 

The  Posterior  Tibial  Absorbents 

Have  been  injected  from  the  under  side  of  the  toes. 
They  accompany  the  ramifications  on  the  sole  of  the 
foot ; and  after  unitiug,  continue  with  the  main  trunk 
up  the  leg,  where  they  enter  the  popliteal  glands. 

The  Peroneal  Absorbents  arise  also  from  the  sole 
of  the  foot,  and  its  external  side.  They  accompany 
the  peroneal  artery,  and  terminate  in  the  popliteal 
glands,  which  receive  also  the  absorbents  from  the 
knee  and  ham. 

Yol.  ii. 


•I1: 

-I 


378  * absorbents  of  the  Lower  Extremity . 

From  these  glands  four  or  five  absorbent  vessels 
proceed,  which  accompany  the  great  blood  vessels  of 
the  lower  extremity;  and,  proceeding  with  them 
through  the  aperture  in  the  tendon  of  the  adductors, 
continue  upwards  until  they  enter  some  of  the  glands 
of  the  groin. 

The  glands  of  the  ham  and  groin,  which  are  so  in- 
timately connected  with  the  absorbents  of  the  lower 
extremity,  are  very  different  from  each  other. 

The  Popliteal  Glands , or  those  of  the  Ham , are 
but  three  or  four  in  number,  and  very  small  in  size. 
They  are  generally  deep-seated,  and  very  near  the 
artery. 

The  Inguinal  Glands  vary  in  number,  from  eight 
to  twelve  or  more.  They  are  superficial  and  deep- 
seated.  The  superficial  communicate  principally 
with  the  superficial  absorbents.  The  lowermost  of 
them  are  at  some  distance  below  Poupart’s  ligament, 
and  the  uppermost  are  rather  above  it.  They  are 
exterior  to  the  fascia  of  the  thigh.  Their  number  is 
generally  six  or  eight,  while  that  of  the  deep-seated 
is  but  three  or  four. 

The  superficial  absorbents  from  below,  approach 
very  near  to  each  other,  and  enter  these  glands. — 
They  are  commonly  distributed  among  three  or  four 
of  the  lowermost ; but  some  of  them  pass  by  these, 
and  proceed  to  one  that  is  higher  up;  and  some- 
times there  are  absorbent  vessels  which  pass  to  the 
abdomen  without  entering  into  any  of  the  glands  of 
the  groin. 

The  deep-seated  absorbents  pass  into  the  deep- 
seated  glands,  which,  as  has  been  already  observed, 
are  but  few,  and  lie  very  near  the  artery  under  the 
fascia  of  the  thigh.  The  two  sets  of  glands  are 
connected  to  each  other  by  many  absorbent  vessels 
that  pass  between  them.  The  vessels  which  finally 
go  out  of  these  glands  are  considerably  less  in  num- 


Inguinal  and  External  Iliac  Glands.  379 

ber  than  those  which  enter  into  them.  They  pro- 
eeed  under  Pou  part’s  ligament,  and,  in  some  in- 
stances, a large  proportion  of  them  passes  through 
three  glands  which  lie  below  this  ligament*  and  are 
often  so  arranged,  that  they  lie  on  each  side  of  the 
great  femoral  vessels,  and  above  them.  One  very 
frequently  is  found  on  the  inside  of  the  femoral  vein, 
in  the  vacuity  between  it  and  the  internal  part  of  the 
ligament.  All  the  absorbents  of  the  lower  extre- 
mity, however,  do  not  enter  these  glands.  Some 
pass  along  the  great  vessels  and  enter  other  glands 
near  the  margin  of  the  pelvis.  Some  also  descend  a 
short  distance  into  the  pelvis,  and  unite  with  vessels 
that  are  passing  from  the  pelvis  to  the  plexus  and  the 
glands  that  surround  the  external  iliac. 

The  absorbents  which  proceed  from  the  glands 
last  mentioned,  joined  to  those  which  pass  under 
Poupart’s  ligament,  without  entering  these  glands, 
and  some  which  come  from  the  pelvis,  form  a large 
plexus,  which  almost  surrounds  the  external  iliac  ves- 
sels, aud  contains  many  glands. 

These  External  Iliac  Glands  vary  in  their  number 
from  six  to  ten  or  twelve.  They  lie  on  the  side  of 
the  pelvis,  in  the  course  of  the  external  iliac  vessels, 
and  some  of  them  are  of  considerable  size.  These 
glands  and  the  plexus  of  absorbents,  extend  in  the 
track  of  the  iliac  vessels,  to  the  first  lumbar  vertebra. 
In  this  course  they  are  joined  by  the  plexus  which 
comes  from  the  pelvis ; and  soon  after  they  arrive  at 
the  Lumbar  Glands , which  form  a very  large  assem- 
blage, that  extends  from  the  bifurcation  of  the  aorta 
to  the  crura  of  the  diaphragm. 

These  glands  lie  irregularly,  on  the  aorta,  the 
vena  cava,  and  the  lumbar  vertebrae.  Most  if  not  all 
the  absorbents  above  mentioned  pass  through  some  of 
them ; and  from  the  union  of  these  absorbents,  some 


380  Absorbents  of  the  Testicles,  fyc. 

of  the  great  brandies,  which  unite  to  form  the  tho- 
racic duct,  are  derived. 

In  this  course  from  the  thigh  to  the  lumbar  glands, 
these  absorbent  vessels  are  joined  by  several  others. 
The  Superficial  Absorbents  of  the  scrotum  commonly 
enter  into  the  upper  inguinal  glands,  and  thus  unite 
to  the  great  body  of  absorbents. 

The  Absorbents  of  the  Testicles,  originate  in  the 
body,  and  the  coats  of  the  testicle,  and  in  the  epi- 
didymis, and  are  remarkably  large  and  numerous. — 
They  proceed  along  the  spermatic  cord,  through  the 
abdominal  ring,  to  the  lumbar  glands.  These  ves- 
sels are  remarkable  for  the  little  communication  they 
have  with  each  other. 

The  Deep-seated  Absorbents  of  the  Scrotum  ac- 
company the  absorbents  of  the  testicle  to  the  lumbar 
glands;  but  those  which  are  superficial  enter  the  up- 
per inguinal  glands. 

The  Absorbents  of  the  Penis  are  also  deep-seated 
and  superficial.  The  deep-seated  arise  from  the 
body  of  the  penis,  and  accompany  the  internal  pudic 
artery  into  the  pelvis.  The  superficial  absorbents 
arise  from  the  prepuce,  and  pass  along  the  dorsum 
of  the  penis.  There  are  frequently  several  trunks 
which  receive  branches  from  the  lower  surface  of 
the  penis  in  their  course.  At  the  root  of  the  penis 
they  generally  separate  to  the  right  and  left,  and  pass 
to  the  glands  on  the  respective  sides. 

In  females,  the  absorbents  of  the  interior  of  the 
clitoris  accompany  the  internal  pudic  artery.  Some, 
which  arise  about  the  vagina,  pass  through  the  abdo- 
minal ring  with  the  round  ! 1 and  ’ rs  pro- 

ceed to  the  inguinal-  glands. 


Absorbents  of  the  Pelvis  and  the  Kidneys.  381 


SECTION  ir. 

Of  the  Absorbents  of  the  Abdomen  and  Thorax. 

The  Absorbents  of  the  lower  portions  of  the  pa- 
rietes  of  the  Abdomen  and  the  Pelvis  unite  into 
trunks  that  follow  the  epigastric,  the  circumflex  and 
the  iliac,  as  well  as  the  lumbar  and  sacral  arteries, 
&c.  They  proceed  to  some  of  the  glands  which  are 
in  the  groin  ; or  in  the  external  iliac,  the  hypogas- 
tric, or  some  of  the  contiguous  plexuses. 

The  Absorbents  of  the  Womb  are  extremely  nu- 
merous; and,  in  the  gravid  state,  are  very  large. 
Those  which  are  on  the  neck  and  anterior  part  of  the 
uterus,  join  the  hypogastric  plexus.  Those  which 
are  on  the  posterior  part  of  the  body,  accompany 
the  spermatic  vessels. 

The  Absorbents  of  the  Bladder  pass  to  small 
glands  on  its  lateral  and  inferior  parts,  and  finally 
join  the  hypogastric  plexus. 

The  Absorbents  of  the  Rectum  are  of  considerable 
size.  They  pass  though  glands  that  lie  upon  that 
intestine,  and  unite  with  the  lumbar  plexus. 

The  Absorbents  of  the  Kidney  are  superficial  and 
deep-seated.  '1  hey  are  very  numerous,  but,  in  a 
healthy  state  of  the  parts,  are  discovered  with  dilli- 
culty.  Cruikshank  describes  them  as  they  appeared, 
filled  with  blood,  iri  consequence  of  pressing  upon 
the  kidney  when  its  veins  were  full  of  blood.  Mas- 
cagni did  not  inject  the  superficial  vessels  with  mer- 
cury ; but  describes  them  as  they  appeared  when 
filled  with  colourless  size,  after  he  had  injected  the 
blood  vessels  of  the  organ  with  the  coloured  fluid. — 
The  deep-seated  absorbents  pass  out  of  the  fissure 
of  the*  kidney  with  the  blood  vessels,  and  unite  with 
the  superficial ; they  proceed  to  the  lumbar  plexus, 
and  pass  into  different  glands. 


382  Lacteals,  or  absorbents  of  the  Intestines. 

Absorbent  vessels  can  be  proved  to  proceed  from 
the  pelvis  of  the  kidney,  and  the  ureters,  by  artifices 
analogous  to  those  above  mentioned. 

The  Gian  dulse  Renales  are  also  supplied  with  ab- 
sorbents, which  are  numerous  in  proportion  to  the 
size  of  the  organs.  They  commonly  join  those  of 
the  kidney. 

The  Absorbents  of  the  Intestines 

Have  generally  been  called  LACTEALS,  from  the 
white  colour  of  the  chyle  which  they  contain  : but 
there  seems  no  reason  for  believing  that  they  are  dif- 
ferent in  their  structure  and  nature  from  the  absorb- 
ents in  other  parts  of  the  body.  A small  number  of 
them  appear  as  if  they  formed  a part  of  the  struc- 
ture of  the  intestines,  and  originated  from  their  ex- 
ternal surface,  as  they  do  in  other  parts  of  the  abdo- 
men ; while  the  principal  part  of  them  are  appro- 
priated to  the  absorption  of  the  contents  of  the  cavity 
of  the  intestines. 

The  first  mentioned  absorbents  run  between  the 
muscular  and  peritoneal  coats,  and  proceed  for  some 
distance  lengthways  on  the  intestine,  while  the  others 
proceed  for  some  distance  within  the  muscular  coat, 
with  the  arteries  ; and  after  passing  through  it,  con- 
tinue between  the  lamina  of  the  mesentery. 

Branches  of  these  different  absorbents  are  frequent- 
ly united  in  one  trunk  so  as  to  prove  that  there  is  no 
essential  difference  between  them. 

The  absorbents  which  come  from  the  internal  sur- 
face of  the  intestines  commence  in  the  villi.  The 
manner  in  which  they  originate  has  been  the  subject 
of  considerable  inquiry,  as  has  been  stated  in  the  ac- 
count of  the  intestines.* 

The  lacteals  or  absorbents  of  the  intestines  are 


rr  See  page  105. 


Lac  teals,  or  Absorbents  of  the  Intestines.  383 

very  numerous.  They  pass  between  the  lamina  of 
the  mesentery  to  glands  which  are  also  seated  be- 
tween those  lamina.  The  number  of  these  glands  is 
very  considerable,*  and  they  are  various  in  size — - 
some  being  very  minute,  and  others  eight  or  ten  lines 
in  diameter.  They  are  generally  placed  at  a small 
distance  from  each  other,  and  are  most  numerous  in 
that  part  of  the  mesentery  which  is  nearest  to  the 
spine.  They  are  almost  always  at  some  distance  from 
the  intestines.  They  appear  to  be  precisely  like  the 
absorbent  glands  in  other  places. 

These  absorbent  vessels,  in  their  course  frequently 
divide  into  branches;  which  sometimes  go  to  the  same 
gland,  sometimes  to  different  glands,  and  sometimes 
unite  with  other  absorbent  vessels.  As  they  proceed, 
they  frequently  enlarge  in  size.  When  they  have  ar- 
rived near  the  spine,  they  frequently  form  three  or 
four  trunks,  and  sometimes  one  or  two  ; which  pro- 
ceed in  the  course  of  the  superior  mesenteric  artery, 
until  they  have  arrived  near  to  the  aorta.  Here  they 
either  pass  into  the  thoracic  duct,  or  descend  and  join 
the  trunks  from  the  inferior  extremities,  to  form  the 
thoracic  duct.  The  absorbents  of  the  great  intestines 
are  not  equal  in  size  to  those  of  the  small;  but  they 
are  numerous.  They  enter  into  glands,  which  are 
very  near,  and  in  some  places,  in  contact  with  the 
intestine;  and  are  commonly  very  small  in  size. 
The  vessels  which  arise  from  the  caecum,  and  the 
right  portion,  as  well  as  the  arch  of  the  colon,  unite 
with  those  of  the  small  intestines ; while  the  vessels 
from  the  left  side  of  the  colon,  and  the  rectum,  pro- 
ceed to  the  lumbar  glands. 

The  absorbents  of  the  intestines  are  frequently 
injected  with  mercury ; but  the  injection  does  not 
proceed  to  their  termination  with  so  much  facility  as 


They  have  been  estimated  between  130  and  150. 


384 


Absorbents  of  the  Stomach. 

it  does  in  others  vessels  cf  the  same  kind.  They 
have,  however,  very  oftt  n been  seen  in  animals,  who 
were  killed  for  the  purpose  after  eating  miik  ; and 
in  several  human  subjects  who  died  suddenly  during 
digestion. — The  description  of  the  origin  of  the 
lactoals,  quoted  in  page  108,  from  Mr.  Cruikshank, 
was  taken  from  a subject  of  this  kind,  of  which  an 
account  is  given  in  his  work  on  the  absorbing  ves- 
sels, p.  59. 

It  is  worthy  of  note,  that  in  several  instances,  in 
which  the  lac  teals  were  thus  found  distended  with 
chyle,  the  glands  in  the  mesentery  were  also  uniform- 
ly white. 

The  Absorbents  of  the.  Stomach 

Are  of  considerable  size,  and  form  three  divisions. 
The  vessels  of  the  first  set  appear  upon  both  sides 
of  the  stomach,  and  pass  through  a few  glands  on 
the  small  curvature  near  the  omentum  minus. — 
From  these  glands  they  proceed  to  others,  which 
are  larger,  and  which  also  receive  some  of  the  deep- 
seated  absorbents  of  the  liver.  The  vessels  from 
these  glands  pass  to  the  thoracic  duct,  near  the  ori- 
gin of  the  eoeliac  artery.  The  second  arise  also  on 
both  sides  of  the  stomach,  and  pass  to  the  left  extre- 
mity of  the  great  curvature  to  unite  with  the  absor- 
bents of  that  side  of  the  great  omentum.  They  then 
proceed  with  the  lymphatics  of  the  spleen  and  pan- 
creas, to  the  thoracic  duct.  The  last  set,  pass  off 
from  the  right  extremity  of  the  great  curvature,  and 
unite  also  with  absorbents  from  the  right  portion  of 
the  omentum.  They  proceed  near  the  pylorus,  and 
go  to  the  thoracic  duct,  with  some  of  the  deep- 
seated  absorbents  of  the  liver. 

Although  the  absorbents  of  the  stomach  are  deep- 
seated,  as  well  as  superficial,  it  is  a general  senti- 
ment, that  they  do  not  contain  chyle  in  the'  human 


Absorbents  of  the  Liver . ,jsj 

subject ; notwithstanding  chyle  has  been  found  in  the 
absorbents  on  the  stomach  of  dogs,  and  some  other 
animals.  It  ought,  however  to  be  remembered,  that 
Sabatier  has,  in  some  instances,  seen  white  lines  on 
the  stomach,  which  he  supposed  to  be  lacteals. 

The  Absorbents  of  the  Liver 

Are  especially  interesting,  because  they  have  been 
more  completely  injected  than  those  of  any  other 
viscus.  They  are  deep-seated  and  superficial . The 
superficial  it  has  been  already  observed  admit  of  in- 
jection in  a retrograde  direction,  and,  therefore,  can 
be  exhibited  most  minutely  ramified.  They  commu- 
nicate freely  with  each  other,  and  also  with  the  deep- 
seated  vessels,  by  their  small  ramifications  ; so  that 
the  whole  gland  has  been  injected  from  one  large 
vessel. 

The  gland  is  so  large,  that  the  absorbents  of  the 
superior  and  inferior  surfaces  proceed  from  it  in  dif- 
ferent directions. 

A large  absorbent  is  generally  found  on  the  sus- 
pensory ligament.  This  is  formed  by  the  union  of 
a great  many  branches  that  arise  both  on  the  right 
and  left  lobes,  but  principally  on  the  right.  It  often 
passes  through  the  diaphragm  at  an  interstice  which 
is  anterior  to  the  xiphoid  cartilage,  and  then  proceeds 
through  glands  on  the  anterior  part  of  the  pericar- 
dium. 

Several  absorbents  proceed  to  the  lateral  ligaments 
on  each  side,  and  then  pass  through  the  diaphragm. 
Some  of  these  branches  return  again  into  the  abdo- 
men, and  the  others  generally  run  forwards  in  the 
course  of  the  ribs,  and  join  those  which  passed  up 
from  the  suspensory  ligament.  The  trunk,  or  trunks, 
formed  by  these  vessels,  either  pass  up  between  the 
lamina  of  the  mediastinum,  and  terminate  in  the  up- 

Vol.  il  49 


386  Absorbents  of  the  Liver  and  Spleen . 

per  part  of  the  thoracic  duct ; or  they  accompany 
the  internal  mammary  arteries,  and  terminate  on  the 
left  side  in  the  thoracic  duct,  and  on  the  right  in  the 
trunk  of  the  absorbents  of  that  side. 

The  Absorbents  on  the  concave  side  of  the  Liver 
are  as  numerous  as  those  on  the  convex  side  ; they 
are  also  very  abundant  on  the  surface  of  the  gall 
bladder.  The  greatest  part  of  them  join  the  deep- 
seated  vessels. 

The  Deep-seated  Absorbents  proceed  in  consider- 
able numbers  front  the  interior  of  the  liver  through 
the  portae.  They  accompany  the  billiary  ducts  and 
the  great  blood  vessels  of  the  organ  ; and,  after 
passing  through  several  glands,  near  the  vena  porta- 
rum,  terminate  in  the  thoracic  duct,  near  the  com- 
mencement of  the  superior  mesenteric  artery. 

Mascagni  states,  that  the  absorbents  of  the  liver 
will  be  distended,  by  injecting  warm  water  into  the 
biliary  ducts,  or  the  vena  portarum. 

He  also  observes,  that  in  those  preparations  in  which 
the  superficial  vessels  are  completely  injected,  in  the 
retrograde  direction,  the  peritoneal  coat  of  the  liver 
appears  to  be  composed  entirely  of  absorbent  vessels ; 
and  to  be  connected  to  the  membrane  within,  by 
many  filaments  which  are  also  absorbent  vessels. 

The  Absorbents  of  the  Spleen 

Are  composed  of  superficial  and  deep-seated  vessels; 
but  they  differ  greatly  from  those  of  the  liver,  in 
this  respect,  that  the  superficial  vessels  are  remark- 
ably small  in  the  human  subject. 

Mascagni  however  asserts,  that  when  the  blood 
vessels  of  the  spleen  are  injected  with  size,  colour- 
ed with  vermilion,  these  absorbents  will  be  filled 
with  colourless  size. 

In  the  spleen  of  the  calf  the  superficial  absorbents 
are  remarkably  large. 


887 


Absorbents-  of  the  Pancreas. 

In  the  human  subject  the  superficial  absorbents  of 
the  spleen  proceed  from  the  convex  to  the  concave 
surface,  and  there  communicate  with  the  deep-seated 
absorbents.,  which  proceed  from  the  interior  of  the 
organ  with  the  blood  vessels. 

These  Beep-seated  Absorbents  are  very  numer- 
ous, and  also  large.  They  accompany  the  splenic 
artery;  and  in  their  course  pass  through  many  glands, 
some  of  which  are  said  to  be  of  a dark  colour.  The 
glands  lie  on  the  splenic  artery,  at  a short  distance 
from  each  other.  The  absorbents  of  the  spleen  re- 
ceive the  absorbents  of  the  pancreas  in  their  course; 
they  unite  with  the  absorbents  of  the  stomach  and 
the  lower  surface  of  the  liver,  and  pass  with  them  to 
the  thoracic  duct. 

Little  has  been  latterly  said  by  practical  anato- 
mists respecting 

The  Absorbents  of  the  Pancreas, 

Mr.  Cruikshank  once  injected  them  in  the  retrograde 
direction  ; he  found  that  they  came  out  of  the  lobes 
of  the  pancreas  in  short  branches  like  the  blood  ves- 
sels, and  passed  at  right  angles  into  the  absorbents 
of  the  spleen,  as  they  accompanied  the  artery  in  the 
groove  of  the  pancreas. 

THE  THORACIC  DUCTf 

Or  common  trunk  of  the  absorbent  system,  is  formed 
by  the  union  of  those  absorbent  vessels  which  are 
collected  on  the  lumbar  vertebrae. 

These  vessels,  as  it  has  been  already  observed, 
are  derived  from  various  sources,  viz. 

The  Lower  Extremities ; the  lower  part  of  the 
Trunk  of  the  Body;  the  Organs  of  Generation;  the 

* First  discovered  by  Eustachius  in  the  horse,  15G4,  but  he  considers  it 
a vein  for  the  nourishment  of  the  thoracic  viscera. — Ed. 


3SS  Commencement  of  the  Thoracic  Duct. 

Intestines,  with  the  other  Viscera  of  the  abdomen 
and  Pelvis,  except  a part  of  the  liver.  Their  num- 
ber is  proportioned  to  the  extent  of  their  origin : for, 
with  the  numerous  glands  appropriated  to  them,  they 
form  the  largest  absorbent  plexus  in  the  body,  and 
are  spread  over  a considerable  portion  of  the  aorta 
and  the  vena  cava. 

The  manner  in  which  these  vessels  unite  to  form 
the  thoracic  duct,  is  very  different  in  different  sub- 
jects; but  in  a majority  of  cases  it  originates  imme- 
diately from  three  vessels,  two  of  which  are  the 
trunks  of  the  absorbents  of  the  lower  extremities, 
and  the  other  is  the  common  trunk  of  the  lacteals  and 
the  other  absorbents  of  the  intestines. 

These  vessels  generally  unite  on  the  second  or 
third  lumbar  vertebrae  ; and,  in  some  instances,  the 
trunk  which  they  form  dilates  considerably,  soon  af- 
ter its  commencement ; in  consequence  of  which  it 
was  formerly  called  the  RECEPTACLE  of  the 
CHYLE.  At  first  it  lies  behind  the  aorta,  but  it 
soon  inclines  to  the  right  of  it,  so  as  to  be  behind  the 
right  crus  of  the  diaphragm.  In  the  thorax,  it  ap- 
pears on  the  front  of  the  spine,  between  the  aorta 
and  the  vena  azygos,  and  continues  between  these 
vessels  until  it  has  arrived  at  the  fourth  or  third  dor- 
sal vertebra.  It  then  inclines  to  the  left,  and  pro- 
ceeds in  that  direction  until  it  emerges  from  the 
thorax,  and  has  arisen  above  the  left  pleura,  when 
it  continues  to  ascend  behind  the  internal  jugular, 
nearly  as  high  as  the  sixth  cervical  vertebrae : it  then 
turns  downward  and  forward,  and,  after  descend- 
ing from  six  to  ten  lines,  terminates  in  the  back  part 
of  the  angle  formed  by  the  union  of  the  left  internal 
jugular  with  the  left  subclavian  vein.  Sometimes, 
after  rising  out  of  the  thorax,  it  divides  into  two 
branches,  which  unite  before  they  terminate.  Some- 
times it  divides,  and  one  of  the  branches  terminates 


Absorbents  of  the  Lungs.  389 

at  the  above  mentioned  angle,  and  the  other  in  the 
subclavian  vein,  to  the  left  of  it. 

The  orifice  of  the  thoracic  duct  has  two  valves, 
which  effectually  prevent  the  passage  of  blood  into 
it  from  the  vena  cava. 

There  are  sometimes  slight  flexures  in  the  course 
of  the  duct;  but  it  generally  inclines  to  the  left,  in 
the  upper  part  of  the  thorax,  as  above  mentioned: 
and  is  then  so  near  the  left  larnen  of  the  mediastinum 
that  if  it  be  filled  with  coloured  injection,  it  can  be 
seen  through  that  membrane,  when  the  left  lung  is 
raised  up  and  pressed  to  the  right. 

The  duct  sometimes  varies  considerably  in  its  dia- 
meter in  different  parts  of  its  course.  About  the  mid- 
dle of  the  thorax  it  has  often  been  found  very  small. 
In  these  cases  it  generally  enlarges  in  its  progress 
upwards,  and  is  often  three  lines  in  diameter,  in  its 
upper  part.  Many  anatomists  have  observed  it  to 
divide  and  to  unite  again,  about  the  middle  of  the 
thorax. 

Absorbents  of  the  Lungs. 

The  absorbents  of  the  lungs  are  very  numerous, 
and,  like  those  of  other  viscera,  are  superficial  and 
deep-seated. 

The  large  superficial  vessels  run  in  the  interstices 
between  the  lobuli,  and  therefore  form  angular  figures 
of  considerable  size.  In  successful  injections,  the 
vacancies  within  these  figures  are  filled  up  with  small 
vessels,  and  the  whole  surface  appears  minutely  in- 
jected. 

Mascagni  observes,  that  the  superficial  vessels  are 
very  visible  when  any  fluid  has  been  effused  into 
the  cavity  of  the  thorax ; or  when  warm  water  is  in- 
jected, either  into  the  blood  vessels  of  the  lungs,  or 
the  ramifications  of  the  trachea.  Cruikshank  de- 
monstrated them  by  inflating  the  lungs  of  a still  born 


390  Absorbents  of  the  Lungs. 

child ; in  which  case  the  air  passes  rapidly  into 
them. 

The  deep-seated  absorbents  accompany  the  blood 
vessels  and  the  ramifications  of  the  bronchi®.  They 
pass  to  the  dark  coloured  glands,  which  are  situa- 
ted on  the  trachea  at  its  bifurcation;  and  on  those 
portions  of  the  bronchi®  which  are  exterior  to  the 
lungs.  The  injection  of  the  absorbents,  which  pass 
to  and  from  these  glands,  seems  to  prove  that  they 
are  of  the  same  nature  with  the  absorbent  glands  in 
general  notwithstanding  their  colour.  They  are  nu- 
merous, and  they  vary  in  size;  from  a diameter  of 
two  lines,  to  that  of  eight  or  ten. 

From  these  glands,  some  of  the  absorbents  of  the 
left  lung  pass  into  the  thoracic  duct,  while  it  is  in 
the  thorax,  behind  the  bifurcation  of  the  trachea; 
others  proceed  upwards  and  enter  into  it  near  its  ter- 
mination; while  those  of  the  right  lung  terminate  in 
the  common  trunk  of  the  absorbents  of  the  right  side0 


CHAPTER  II. 


OF  THE  ABSORBENTS  OF  THE  HEAD  AND  NECK  ; OF 

THE  UPPER  EXTREMITIES,  AND  THE  UPPER  PART 

OF  THE  TRUNK  OF  THE  BODY. 

The  absorbents  from  the  various  parts  of  the  head 
pass  through  glands,  which  are  situated  on  the  neck, 
or  the  lower  part  of  the  head.  Those  on  the  head 
are  the  least  numerous,  and  also  the  least  in  size. — 
Some  of  them,  which  are  generally  small,  lie  about 
the  parotid  gland.  Several  of  them,  which  are  also 
small,  are  on  the  occiput,  below  and  behind  the 
mastoid  process.  Sometimes  there  are  two  or  three 
on  the  cheek,  near  the  basis  of  the  lower  jaw,  about 
the  anterior  edge  of  the  masseter  muscle.  Below  the 
lower  jaw,  in  contact  with  the  sub-maxillary  gland 
and  anterior  to  it,  there  are  always  a number  of  these 
glands,  which  are  generally  small,  but  often  swelled 
during  infancy. 

The  Glands  on  the  JYech  are  the  most  numerous. 
Many  of  them  are  within  the  sterno- mastoid  muscle, 
and  accompany  the  internal  jugular  vein  and  the 
carotid  artery  down  to  the  first  rib.  Many  also  lie 
in  the  triangular  space  between  the  sterno- mastoid 
muscle,  the  trapezius,  and  the  clavicle  ; therefore  it 
has  been  truly  said  thpt  the  glands  of  the  neck  are 
more  numerous  than  those  of  any  other  part,  except 
the  mesentery.  They  are  frequently  called  Glan- 
dulse  Concatenatae.  It  has  already  been  mentioned 
that  the  various  absorbents,  which  are  connected  with 
these  glands,  unite  on  each  side  into  a trunk,  which 
on  the  left  passes  into  the  thoracic  duct,  and  on  the 
right  into  the  common  trunk  of  the  absorbents  of 
that  side. 


392  Absorbents  of  the  Head  and  JYeck . 

SECTION  i. 

Of  the  Absorbents  of  the  Head  and  Neck. 

There  is  the  greatest  reason  to  believe  that  the 
brain  and  its  appendages  are  supplied  with  absorb- 
ents like  the  other  parts.  Some  of  these  vessels  have 
been  discovered  in  the  cavity  of  the  cranium ; but 
very  little  precise  information  has  as  yet  been  obtain- 
ed, respecting  the  extent,  or  arrangement  of  the  ab- 
sorbent system,  in  this  part  of  the  body. 

The  absorbents  on  the  exterior  of  the  head  are  as 
numerous  as  in  other  parts  of  the  body.  On  the  oc- 
ciput they  pass  down,  inclining  towards  the  ear,  and 
continue  behind  it  to  the  side  of  the  neck ; behind 
the  ear  they  pass  through  several  glands. — From  the 
middle  or  temporal  region  of  the  cranium,  they  pass 
with  the  carotid  artery  before  the  ear,  and  enter  some 
small  glands  that  lie  on  the  parotid  ; from  which  they 
continue  to  the  neck. 

They  are  on  every  part  of  the  face,  and  unite,  so 
that  their  principal  trunks,  which  are  very  numerous, 
pass  over  the  basis  of  the  lower  jaw,  near  the  facial 
artery.  They  enter  into  glands,  which  are  also  very 
numerous,  immediately  under  the  jaw,  or  which  are 
sometimes  to  be  found  on  the  cheek,  at  the  anterior 
edge  of  the  masseter  muscle.  All  the  absorbents  of 
the  exterior  part  of  the  head  pass  to  the  glands  on 
the  side  of  the  neck,  already  described. 

Those  from  the  interior  of  the  nose  accompany  the 
ramifications  of  the  internal  maxillary  artery,  and 
proceed  to  glands  behind  the  angle  of  the  lower  jaw; 
into  which  glands  also  enter  the  absorbents  of  the 
tongue  and  inner  parts  of  the  mouth. 

The  absorbents  of  the  thyroid  gland,  on  the  left 
side,  pass  down  to  the  thoracic  duct;  those  on  the 
right,  unite  to  the  trunk  of  the  absorbents  on  that 


393 


Absorbents  of  the  Hand  and  Ann , 

side,  near  its  termination.  It  has  been  remarked  that 
they  can  be  readily  injected,  by  thrusting  the  pipe 
into  the  substance  of  the  gland. 

SECTION  II. 

Of  the  Absorbents  of  the  Arm  and  Upper  Part  of 
the  Trunk . 

The  absorbents  of  the  arm  are  superficial  and  deep- 
seated,  like  those  of  the  lower  extremity. 

The  superficial  absorbents  have  been  injected  on 
the  anterior  and  posterior  surfaces  of  the  fingers  and 
the  thumb,  near  their  sides.  On  the  back  of  the 
hand  they  are  very  numerous,  and  increase  consi- 
derably in  their  progress  up  the  fore-arm.  As  they 
proceed  upwards,  they  incline  towards  the  anterior 
surface  of  the  fore-arm ; so  that  by  the  time  they  have 
arrived  at  the  elbow,  almost  all  of  them  are  on  the 
anterior  surface.  The  absorbents  on  the  anterior  part 
of  the  hand  are  not  so  numerous  as  those  on  the  back. 
Sometimes  there  are  digital  branches  from  the  fin- 
gers, and  an  arcus  in  the  palm ; but  this  bow  is  not 
formed  by  one  large  absorbent,  analogous  to  the  ulnar 
artery.  On  the  contrary,  its  two  extremities  are  con- 
tinued over  the  wrist,  and  pass  on  the  fore-arm  like 
the  absorbents. 

At  the  elbow,  some  of  them  often  pass  into  one  or 
two  small  glands,  which  are  very  superficial;  but 
the  whole  of  the  absorbents,  somewhat  reduced  in 
number,  as  some  of  them  unite  together,  pass  along 
with  the  bloodvessels  into  the  hollow  of  the  arm-pit; 
where  they  enter  the  axillary  glands.  There  are 
generally  one  or  more  vessels  which  pass  in  the 
course  of  the  cephalic  vein,  between  the  pectoral  and 
the  deltoid  muscle,  and  enter  into  some  of  the  glands 
under  the  clavicle. 

VOL,  II, 


50 


394  Absorbents  of  the  Upper  Part  of  the  Trunk. 

There  are  almost  always  several  glands  in  and 
near  the  axilla.  Some  of  them  are  very  near  the 
great  blood  vessels ; sometimes  one  or  more  of  them 
are  much  lower;  sometimes  they  are  to  be  found 
under  the  pectoral  muscle.  They  are  commonly  not 
so  large  as  those  of  the  groin,  and  are  surrounded 
with  fat. 

The  deep-seated  absorbents  originate  also  at  the 
fingers,  and  soon  accompany  the  branches  of  the  ar- 
teries. Those  which  attend  the  radial  artery,  origi- 
nate on  the  back  of  the  hand,  and  also  in  the  palm, 
where  they  are  associated  with  the  arcus  profundus. 
They  go  up  with  the  radial  artery  to  the  elbow,  and 
sometimes  pass  through  a small  gland  about  the  mid- 
dle of  the  fore-arm. 

Those  which  attend  the  ulnar  artery,  commence 
under  the  aponeurosis  palmaris,  and  go  with  the  ar- 
tery to  the  elbow;  at  the  bend  of  the  elbow  they  are 
generally  joined  by  one  or  more,  which  accompany 
the  interosseal  artery  ; there  they  unite,  so  as  to  form 
several  trunks  which  pass  up  to  the  axillary  with  the 
humeral  artery.  They  sometimes  pass  through  one 
or  two  glands,  which  are  near  the  elbow ; and  they 
receive  in  their  course,  deep-seated  branches  from 
the  muscles  on  the  humerus. 

The  absorbents  from  the  anterior  and  external 
part  of  the  thorax,  and  the  upper  part  of  the  abdo- 
men, also  proceed  to  the  axilla,  and  enter  into  the 
glands  there ; those  which  are  deep  seated,  joining  the 
deep-seated  vessels.  The  absorbents  of  the  mammae 
pass  to  the  same  glands;  and  when  they  are  affected 
with  the  virus  of  cancer,  can  often  be  perceived,  in 
their  course,  in  the  living  subject. 

The  absorbents  of  the  uppermost  half  of  the  back, 
and  those  of  the  back  of  the  neck,  go  likewise  to  the 
axilla. 

The  absorbent  vessels,  collected  from  these  van- 


Facts  relating  to  Cutaneous  Absorption.  395 

ous  sources,  proceed  from  the  exterior  to  the  inner- 
most glands,  but  with  a considerable  diminution  of 
their  number;  they  accompany  the  subclavian  vein, 
and  are  reduced  to  one  or  two  trunks,  that  gene- 
rally unite  before  their  termination.  On  the  left 
side , the  absorbents  of  the  head  and  neck  generally 
open  into  the  thoracic  duct,  as  has  been  already  ob- 
served; and  those  of  the  left  arm  also  open  into  the 
thoracic  duct,  or  into  the  subclavian  vein  very  near 
it.  On  the  right  side  the  absorbents  from  each  of 
these  parts  empty  into  the  common  trunk;  which 
often  is  formed  by  the  union  of  large  vessels,  from 
four  sources;  viz.  the  Head,  the  Thyroid  gland,  the 
right  arm,  and  the  right  cavity  of  the  Thorax,  &c. 
The  diameter  of  the  trunk  is  very  considerable ; but 
it  is  often  not  more  than  half  an  inch  in  length.  It 
generally  opens  into  the  right  subclavian  vein,  at 
the  place  where  it  unites  to  the  right  internal  ju- 
gular. 

Two  respectable  physiologists  of  Europe,  (M.  Seguin,  of 
Paris,  and  the  late  Dr.  Currie,  of  Liverpool,)  have 
doubted  whether  absorption  takes  place  on  the  exter- 
nal surface  of  the  skin.*  This  question  has  been  ex- 
amined in  a very  interesting  manner  by  several  gra- 
duates of  the  University  of  Pennsylvania,  who  chose 
it  for  the  subject  of  their  inaugural  theses  ; viz.  Drs. 
Rousseau,  Klapp,  Daingerfield,  Mussey,  and  J.  Brad- 
ner  Stewart. 

The  three  first  of  these  gentlemen  state,  that  when  spirit 
of  turpentine,  and  several  other  substances  which  are 
commonly  supposed  to  be  absorbed  by  the  skin,  were 
applied  to  it  in  a way  which  prevented  their  volatile 

* I believe  that  M.  Seguin’s  Memoir  on  this  subject  was  read  to  the 
Academy  of  Sciences  a short  time  before  the  meetings  of  that  body  were 
suspended.  It  was  published  by  M.  Fourcroy,  in  La  Medicine  Eclairee 
par  les  Sciences  Physiques,  vol.  iii.  An  extract  from  M.  Fourcroy’s  pub- 
lication may  be  se*n  in  the  19th  chapter  of  the  first  volume  of  Dr.  Currie’s 
<!  Medical  Reports  on  the  Effects  of  Water,”  &c.  in  which  is  also  con- 
tained a statement  of  the  Doctor’s  own.  experiments  and  reflections. 


396  Experiments  of  K.  Boerhaewe  and  J.  Hunter . 

parts  from  entering  the  lungs  by  respiration,  no  ab- 
sorption took  place.  But  when  they  inspired  air  im- 
pregnated with  exhalations  from  these  substances,  they 
perceived  satisfactory  proofs  that  the  exhalations  en- 
tered the  system.  From  these  facts  they  inferred  that 
when  those  articles  entered  the  body  by  absorption, 
they  were  taken  in  by  the  lungs,  and  not  by  the  exter- 
nal surface. 

On  the  other  hand,  the  two  gentlemen  last  mentioned, 
state  that  alter  immersing  themselves  in  a bath  con- 
sisting ol  a decoction  of  rhubarb,  of  madder,  or  of  tur- 
meric, their  urine  became  tinged  with  these  sub- 
stances. They  also  assert  that  the  colouring  matter 
of  these  different  articles  is  not  volatile  ; and,  there- 
fore, could  not  have  entered  the  lungs  during  the  ex- 
periments.* 

The  statement  in  page  374,  from  Dr.  Soemmering,  that 
when  mercury  is  injected  backwards  in  the  absorbent 
vessels  which  originate  on  the  foot,  it  will  sometimes 
appear  in  small  globules  on  the  skin  of  the  foot,  has 
an  important  connexion  with  this  subjeett 


About  the  middle  of  the  last  century,  it  was  generally 
believed  by  anatomists,  that  absorption  was  performed 
by  the  veins.  This  doctrine  seemed  to  be  established 
by  the  experiments  of  Kaaw  Boerhaave,  which  are  re- 
lated, with  many  other  interesting  statements,  in  his 
work,  entitled  “ Perspiratio  Dicta  Hippocrati,”  &c. 
published  at  Leyden,  in  1738.  In  these  experiments 
it  appeared  to  the  author,  that  when  the  stomach  of  a 
dog  was  emptied  of  its  contents,  and  filled  with  w arm 
water,  immediately  alter  death,  the  water  passed  into 
the  minute  ramifications  of  the  veins  of  the  stomach, 

* The  Thesis  of  Dr.  Rousseau  was  published  in  1800.  Those  of  Drs. 
Klapp  and  Daingerfield  in  1805.  Dr.  Mussey  published  in  the  Third 
Supplement  to  the  Medical  and  Physical  Journal  of  Dr.  Barton,  in  1809. 
Dr.  Stewart  published  in  1810.  Additional  observations  by  Drs.  Klapp, 
Rousseau  and  Smith,  are  published  in  the  Philadelphia  Medical  Museum, 
Vol.  i.  new  series. 

f Since  the  publication  of  the  first  volume,  the  author  has  enjoyed  the 
advantage  of  consulting  a translation,  in  manuscript,  of  some  parts  of  the 
German  edition  of  Dr.  Soemmering’s  valuable  work  op  the  Structure  of 
rhe  Human  Body 


'Experiments  of  Magendie  and  Delile . 397 

and  from  them  to  the  vena  portarum,  and  ultimately 
to  the  heart,  in  large  quantities. 

This  account  appears  to  be  disproved  by  some  experi- 
ments of  the  late  John  Hunter,  made  about  twenty 
years  after,  and  published  in  the  Medical  Commenta- 
ries of  Dr.  William  Hunter,  Part  I. Mr.  Hunter’s 

experiments  have  been  considered  as  establishing  the 
fact,  that  absorption,  (in  the  intestines  at  least,)  is  per- 
formed exclusively  by  the  lacteals,  or  proper  absorbent 
vessels,  and  not  at  all  by  the  veins.  Kaaw  Boer- 
haave  is  of  course  supposed  to  have  been  mistaken  | 
and  Mascagni,  who  has  repeated  his  experiment,  re- 
fers the  appearance  of  water  in  the  veins  to  transuda- 
tion through  the  coats  of  the  intestines  ; which  he  has 
observed  to  take  place  to  a great  degree. 

In  the  year  1809,  a memoir  was  presented  to  the  nation- 
al institute  of  France  by  Messrs.  Magendie  and  De- 
lile, which  contains  an  account  of  some  experiments 
that  have  an  important  relation  to  the  above  mentioned 
subject.* — The  authors  being  greatly  surprised  at  the 
rapidity  with  which  the  poison  of  Java,  &c.  appeared 
to  enter  the  sanguiferous  system,  instituted  a series 
of  experiments  to  determine  whether  these  substances 
proceeded  to  that  system  by  the  circuitous  route  of  the 
absorbent  vessels,  or  by  the  shorter  course  of  the  veins. 
Two  of  their  experiments  are  especially  interesting. 
They  made  an  incision  through  the  parietes  of  the  ab- 
domen of  a living  dog,  who  had  eaten  a large  quantity 
of  meat  some  hours  before,  (that  his  lacteals  might  be 
visible  from  their  distension  with  chyle,)  and,  draw- 
ing out  a portion  of  the  small  intestine,  they  applied 
two  ligatures  to  it,  at  the  distance  of  five  inches  from 
each  other.  The  portion  of  intestine  between  these 
ligatures  was  then  separated  by  incision  from  the  rest 
ot  the  intestinal  tube,  and  all  the  lacteals,  blood  ves- 
sels, &c.  which  passed  to  and  from  it,  were  divided, 
except  one  artery  and  a vein.  A considerable  length 
of  this  artery  and  vein  were  detached  from  all  the  sur- 
rounding parts,  so  that  the  authors  supposed  these 

' The  title  of  the  paper  is  a “ Memoir  on  the  Organs  of  Absorption 
in  Mammiferous  Animals.”  A translation  of  it  was  published  in  the  Me- 
dical and  Philosophical  Register  of  New  York,  and  in  several  other  perio- 
dical works. 


398  Experiments  of  Magendie  and  Delile . 

vessels  to  form  the  only  connexion  between  the  por- 
tion of  the  intestine  and  the  rest  of  the  body.  Into 
the  cavity  of  the  intestine,  which  was  thus  circum- 
stanced, they  introduced  a small  quantity  of  the  poison, 
and,  to  their  astonishment,  it  produced  its  fatal  effects 
in  the  same  manner  it  would  have  done  if  it  had  been 
introduced  into  the  intestine  while  all  its  connexions 
with  the  body  were  entire.  This  experiment,  they 
assert,  was  repeated  several  times,  without  any  dif- 
ference in  the  result. 

After  several  other  experiments,  they  finally  separated 
the  thigh  from  the  body  of  a living  dog  in  such  a man- 
ner that  the  crural  artery  and  vein  were  left  undivi- 
ded. A quill  was  then  introduced  into  the  artery, 
and  two  ligatures  were  applied  to  fix  it  round  the 
quill.  The  artery  was  then  divided  between  the  two 
ligatures.  The  vein  was  managed  in  the  same  man- 
ner. There  was,  therefore,  no  communication  be- 
tween the  limb  and  the  body,  except  by  the  blood 
which  passed  through  the  divided  vessels  and  the 
quills.  The  poison  was  then  introduced  under  the 
skin  of  the  foot,  and  soon  occasioned  the  death  of  the 
animal : its  deleterious  effects  commencing  about  four 
minutes  after  its  application  to  the  foot.  This  expe- 
riment appears  to  prove  decidedly  that  the  blood  is  the 
vehicle  by  which  poison,  when  applied  to  the  extremi- 
ties, is  carried  to  the  body  ; although  it  may  not  de- 
termine the  question  whether  this  poison  was  taken 
up  by  the  absorbents  or  by  the  veins.* 

Some  other  experiments  made  by  the  authors  gave  re- 
sults, which  are  very  difficult  indeed  to  explain.  They 
wished  to  know  if  the  blood  of  an  animal  thus  con- 
taminated, would  produce  similar  effects  upon  another 
animal;  and,  with  a view  to  ascertain  this  point,  they 
insinuated  a small  piece  of  wood,  covered  with  the 
poison,  into  the  thick  part  of  the  left  side  of  the  nose 
of  a dog.  Three  minutes  after  the  introduction  of  the 
poison,  they  transfused  blood  from  the  jugular  vein  of 
the  same  side,  into  one  of  the  veins  or  another  dog. 
About  one  minute  after  the  commencement  of  the 

* This  experiment  has  been  repeated  in  Philadelphia.  See  Professor 

Chapman’s  Medical  and  Physical  Journal  for  February,  1823,  No.  10. 

FiJD- 


Report  of  the  Committee  of  the  Institutes . 399 

• transfusion,  the  effects  of  the  poison  began  in  the  dog 
to  which  it  was  applied,  and  continued  until  his  death. 
Transfusion  into  the  vehis  of  the  other  dog  went  on 
during  the  whole  time,  and  he  received  a large  quan- 
tity of  blood  from  the  dying  dog,  without  producing 
any  effect. — They  varied  this  experiment  in  the  fol- 
lowing manner.  The  thigh  of  a dog  was  separated 
from  the  body;  the  artery  and  the  vein  were  arranged 
as  in  the  former  experiment;  and  poison  was  intro- 
duced into  the  foot.  Three  minutes  after  the  intro- 
duction of  the  poison,  the  blood  of  the  crural  vein  was 
passed  into  the  jugular  vein  of  another  animal,  and 
transfusion  was  continued  five  minutes  without  pro- 
ducing any  effect  upon  the  animal  receiving  the  blood; 
it  was  then  stopped,  and  the  crural  vein  was  so  ar- 
ranged that  the  blood  flowed  from  it  into  the  animal 
to  which  it  belonged.  This  animal  very  soon  exhibit- 
ed symptoms  of  the  operation  of  the  poison.* 

From  these  very  interesting  experiments  the  authors  in- 
fer that  “ foreign  matters  do  not  always  proceed 
through  the  lymphatic  or  Absorbent  Vessels,  when 
they  enter  into  the  Sanguiferous  system.  ” 

This  memoir  was  referred  by  the  Institute  to  four  of  its 
members,  who  are  particularly  distinguished  by  their 
profound  knowledge  of  anatomy  and  physiology. 
These  gentlemen,  after  stating  their  belief  that  the 
functions  of  the  lymphatic  or  absorbent  system  have 
been  completely  ascertained  by  the  experiments  and 
observations  of  Hunter,  Cruikshank,  Mascagni,  &c, 
say  further,  that,  in  their  opinion,  the  above  mention- 
ed inference  ought  to  be  a little  modified,  and  that 
facts  are  not  sufficiently  numerous,  or  applicable  to 
the  point  in  question,  to  justify  the  inference  that 
foreign  matters  do  not  always  proceed  through  the 
Lymphatic  or  Absorbent  Vessels,  when  they  enter  the 
Sanguiferous  system.  But  they  also  add,  that,  as  the 
author  is  still  engaged  in  a series  of  experiments  on 
the  subject,  they  will  suspend  their  judgment  respect- 
ing  the  inferences  to  be  deduced  from  the  present 
statement. 

* An  account  of  these  experiments  was  published  by  M.  Magendie  in  a 
pamphlet.  A statement  of  them  is  also  contained  in  the  report  made  to 
the  Institute  by  the  committee  to  whom  the  memoir  was  referred,  which  is 
published  in  the  Journal  de  Physique,  for  March  1813.  In  that  statement 
this  last  mentioned  experiment  is  omitted. 


400 


Of  the  Absorbent  System. 

The  most  extensive  account  of  the  absorbent  system  is 
contained  in  the  “ Historia  et  Ichnographia  Yasorum 
Lymphaticorum  Corporis  Humani”  of  Mascagni. — 
“ The  Anatomy  of  the  Absorbing  Vessels  of  the  Human 
Body,  by  W.  Cruikshank  — and  “ The  Description 
of  the  Lymphatic  System,  by  Wm.  Ilewson,”  (the 
second  volume  of  his  Experimental  Inquiries,) — are 
also  very  interesting  publications. 

A most  interesting  series  of  inquiries  and  experiments  in  regard  to  the 
laws  of  absorption  will  be  found  in  Professor  Chapman’s  Journal  of  the 
Medical  and  Physical  Sciences,  No.  6,  in  a report  of  a Committee  of  the 
Academy  of  Medicine,  signed  by  Doctors  Lawrance  and  Coates,  of  this 
city. — And  a continuation  of  the  same  will  be  found  in  No.  10,  of  the  same 
Journal,  signed  by  Doctors  Lawrance  and  Coates.  Since  the  publication 
of  the  latter,  to  the  regret  of  all  who  knew  him,  and  to  the  great  loss  of 
Anatomy  and  of  Physiology,  the  indefatigable  and  excellent  Lawrance 
Is  no  more. — Eb. 


APPENDIX. 


OF  THE  BLOOD. 

THE  blood  of  a healthy  person  indicates  a ten= 
dency  to  coagulate  very  soon  after  it  is  discharged 
from  the  vessels  which  naturally  contain  it,  although 
it  is  perfectly  fluid  in  those  vessels. 

If  it  remain  at  rest,  after  it  is  drawn  from  the 
vessels,  it  soon  coagulates,  into  a solid  mass,  of  a soft 
texture.  From  this  solid  mass  a fluid  is  soon  ob- 
served to  issue,  which  first  appears  in  very  small 
drops  on  almost  every  part  of  the  surface.  These 
drops  quickly  increase  and  run  together,  and  in  a 
short  time  the  fluid  surrounds  the  solid  mass,  and  ex- 
ceeds it  in  quantity. 

The  solid  part  which  thus  appears  upon  the 
spontaneous  separation  of  the  blood,  is  denominated 
Crassamentum  or  Cruror:  the  fluid  part  is  called 
Serum. 

The  substance  which  contains  the  red  colour  of  the 
blood  remains  with  the  Crassamentum.  The  Serum , 
when  it  separates  without  agitation,  is  free  from  the 
red  colour. 

The  colouring  matter  may  be  separated  completely 
from  the  Crassamentum  by  washing  it  with  water. 

The  blood,  therefore,  consists  of  three  parts,  viz. 
the  Serum  ; the  Substance  which  coagulates  spon- 
taneously ; and  the  Colouring  Matter . 

VOL.  ii.  51 


402 


Appendix.— Of  the  Blood. 


THE  SERUM 

Has  a considerable  degree  of  consistence,  although 
it  is  much  thinner  than  blood.  In  its  perfectly  na- 
tural state,  it  is  almost  transparent,  and  appears  to 
be  very  lightly  tinged  with  a greenish  yellow  colour; 
but  it  is  very  often  impregnated  with  a portion  of 
bile,  which  is  probably  carried  to  the  blood  vessels 
by  the  absorbents.  It  contains  a large  quantity  of 
albumen,  or  matter  like  the  white  of  an  egg.  If 
heated  to  140°  of  Fahrenheit,  it  becomes  opaque  ; 
and  when  the  heat  is  increased  to  156  or  160,  it  is 
firmly  coagulated.  It  is  also  coagulated  by  alcohol, 
by  mineral  acids,  and  by  rennet.*  It  is  proved  by 
chemists,  that  it  contains  a small  quantity  of  pure 
soda.  It  therefore  changes  several  of  the  blue  co- 
lours of  vegetables  green.  It  is  also  found  to  con- 
tain a similar  quantity  of  the  muriate  and  the  phos- 
phate of  soda,  and  the  phosphate  of  lime.  These 
saline  substances  were  discovered  by  diluting  serum 
with  water,  and  exposing  the  mixture  to  heat,  by 
which  the  albumen  was  coagulated  into  flocculi : 
these  flocculi  were  separated  by  filtration  : the  li- 
quor was  then  diminished  by  evaporation,  and  the 
salts  obtained  from  it  by  crystallization. 

Serum  likewise  contains  a portion  of  sulphur  com- 
bined with  ammonia. 

When  it  is  exposed  to  a coagulating  heat,  a small 
portion  of  it  remains  fluid. 

This  fluid  portion  has  been  supposed  to  contain  a 
considerable  quantity  of  gelatine  ; but  it  is  contend- 
ed by  Mr.  Brande,f  that  Gelatine  does  not  exist  in 

* See  Hewson,  Vol  I.  p.  139. — I suspect  that  some  particular  manage- 
ment is  necessary  in  the  use  of  rennet. 

f In  his  Researches  on  the  Blood  communicated  to  the  Royal  Society 
of  London,  in  1812,  and  republished  in  the  Eclectic  Repertory,  for  April, 
1S1? 


403 


Appendix.— Of  the  Blood. 

the  serum  of  the  blood,  and  that  this  portion  consists 
of  albumen  combined  with  a proportion  of  alkali. 

It  is  also  asserted  by  Dr.  Bostoek,*  one  of  the 
latest  writers  on  the  subject,  that  the  serosity  of  the 
blood,  (the  term  applied  to  the  last  mentioned  fluid,) 
contains  no  gelatine  ; but  that,  with  a minute  quan- 
tity of  albumen,  it  consists  of  a large  portion  of  an 
animal  matter,  which  is  different  either  from  gela- 
tine or  albumen,  being  unlike  either  of  them  in  its 
chemical  qualities. 

THE  CRASSAMENTUM 

Is  rendered  very  different  in  its  appearance,  by  the 
different  circumstances  in  which  it  may  coagulate. 

When  the  blood  remains  at  rest  immediately  after 
it  is  drawn,  the  crassamentum  which  forms  in  it  is  a 
concrete  substance,  without  the  smallest  appearance 
of  fibre  in  its  composition.  If  the  blood  is  stirred 
with  a rough  stick,  while  it  is  flowing  from  an  ani- 
mal, a large  portion  of  it  will  concrete  upon  the 
stick  in  a fibrous  form,  so  as  to  resemble  a mass  of 
entangled  thread,  some  of  the  red  colouring  matter 
still  adhering  to  it. 

The  crassamentum,  in  either  of  these  forms,  may 
be  washed  perfectly  white  ; the  red  colouring  matter 
passing  completely  away  with  the  water.  In  this 
state  it  appears-)-  to  have  all  the  chemical  properties 
of  the  fibrous  matter  of  muscular  flesh.  It  also  resem- 
bles the  gluten  of  vegetables,  being  soft  and  elastic. 
The  name  fibrin  is  now  generally  applied  to  it. 

If  fibrin  is  washed  and  dried,  its  weight  is  very 
small  indeed  when  compared  with  that  of  the  blood 

* See  his  observations  on  the  Serum  of  the  Blood,  in  the  Medico-Chi- 
rurgical  Transactions,  Vol.  II.  republished  in  the  Eclectic  Repertory,  for 
October  1812. 

t By  the  experiments  of  Mr.  Charles  Hatchett,  published,  in  the  London 
Philosophical  Transactions  for  1800- 


404  Appendix.— Of  the  Blood. 

from  which  it  has  been  obtained.  It  is,  therefore? 
probable  that  a considerable  proportion  of  the  bulk 
of  the  crassamentum,  as  it  forms  spontaneously,  de- 
pends upon  the  serum  which  exists  in  it,  and  can  be 
washed  away. 

The  spontaneous  coagulation  of  the  blood,  which 
appears  to  depend  principally  upon  the  Fibrin , may 
be  prevented  by  the  addition  of  several  foreign  sub- 
stances to  the  blood,  when  it  is  drawn.  It  is  subject 
to  great  variations  that  depend  upon  the  state  of  the 
body  at  the  time  of  bleeding  ; and  in  some  condi- 
tions, it  does  not  take  place  at  all.* 

In  a majority  of  dead  subjects  the  blood  is  found 
more  or  less  coagulated  in  the  veins ; but  in  some 
subjects  it  is  found  without  coagulation.  It  is  assert- 
ed that  it  does  not  coagulate  in  subjects  who  have 
died  suddenly,  in  consequence  of  anger,  lightning, 
or  a blow  on  the  stomach. 


THE  COLOURING  MATTER. 

When  the  blood  vessels  in  the  transparent  parts  of 
certain  living  animals  are  examined  with  magnifying 
glasses,  it  appears  that  the  red  colour  of  the  blood 
is  owing  to  bodies  of  a globular  form,  which  are  dif- 
fused through  a transparent  fluid.  The  appearance 
of  these  bodies  has  been  examined,  with  great  atten- 
tion, by  many  physiologists,  since  the  publication  of 
Leuwenhoeck,  in  the  London  Philosophical  Trans- 
actions, t 

* See  an  Inquiry  into  the  Properties  of  the  Blood,  by  the  late  Win. 
Hewson:  and  Experiments  by  his  son,  T.  T.  Hewson,  in  the  Eclectic 
Repertory,  Jan.  1811 — See  also  a Treatise  on  the  Blood,  &c.  by  the  late 
J.  Hunter. 

t Among  the  most  distinguished  of  these  observers  were  Father  de  la 
Torre,  Haller,  Hewson,  Fontana,  Spalanzani,  J.  Hunter,  Cavallo. 

Some  short  accounts  of  Leuwenhoeck’s  original  observations  on  the 
blood  are  to  be  found  in  the  Philosophical  Transactions  of  l^ondon;  for 


405 


Appendix  .—Of  the  Blood. 

Several  of  these  gentlemen  have  described  the  ap- 
pearance of  the  blood  very  differently  ; but  Haller, 
Spalanzani  and  J.  Hunter  agree  that  the  figure  of 
the  red  particles  is  globular.*  Hunter  observes 
further,  that  the  red  globules  do  not  run  into  each 
other  as  two  globules  of  oil  would  do  when  divided 
by  water  ; and  he  believes  that  they  cannot  unite.— 
At  the  same  time  they  seem  not  to  have  the  proper- 
ties of  a solid : for  when  circulating  in  the  vessels, 
they  assume  elliptical  forms,  adapting  themselves  to 
the  size  of  the  vessels.  They  also  excite  no  sensa- 
tion of  solidity  when  touched. 

They  appear  to  be  more  heavy  than  the  other 
parts  of  the  crassamentum : for  in  healthy  blood  the 
lower  part  of  the  mass  contains  more  of  the  colour- 
ing matter  then  the  upper  part;  and  in  the  blood  of 
persons  who  labour  under  acute  local  inflammation, 
they  often  subside  completely  from  the  upper  part ; 
and  thus  occasion  what  is  called  by  Mr.  Hewson,  the 
inflammatory  crust,  or  size. 

It  has  been  observed  by  Mr.  Hewson,  and  also 
by  Mr.  Hunter,  that  the  globules  do  not  retain  their 
form  in  every  fluid.  They  are  said  to  be  dissolved 


1664,  in  the  fasciculi  which  are  numbered  102  and  106.  A more  full  de- 
scription is  contained  in  Boerhaave’s  Academical  Lectures  on  the  Theory 
of  Physic.  See  the  section  on  the  nature  of  the  blood. 

The  glasses  of  Father  de  la  Torre  were  transmitted  from  Naples  to  the 
Royal  Society  of  London  in  1765.  They  were  accompanied  by  a letter 
from  Sir  F.  H.  E.  Stiles,  to  which  are  subjoined  some  observations  by  the 
Rev.  Father  himself.  The  letter  and  the  observations  are  published  in  the 
55th  volume  of  the  Transactions  of  that  society. 

In  the  year  1798,  Tiberius  Cavallo  published  an  Essay  on  the  Medicinal 
Properties  of  Factitious  Air,  with  an  Appendix  on  the  Nature  of  the 
Blood,  in  which  is  contained  a further  account  of  the  glasses  of  de  la 
Torre. 

* I believe  that  this  is  also  the  opinion  of  Fontana. — In  J.  Hunter’s 
work  en  the  Blood  there  are  some  interesting  observations  on  micro- 
scopical deceptions.  See  the  note,  commencing  in  page  39,  Bradford’s 
edition. 


406  Appendix  .—Of  the  Blood. 

very  quickly  in  water,  and  then  they  form  a fine 
clear  red.  Several  of  the  neutral  salts,  when  dis- 
solved in  water,  prevent  the  solution  of  the  globules. 
Mr.  Hunter  informs  us,  that  the  vitriolic  acid,  when 
greatly  diluted,  does  not  dissolve  them,  &c.  The 
muriatic  acid,  when  three  times  as  strong  as  vinegar, 
destroys  their  colour  without  dissolving  them,  al- 
though when  more  diluted,  it  dissolves  them. 

The  colour  of  the  blood  has,  for  a long  time,  been 
supposed  to  depend  upon  Iron.  About  the  middle 
of  the  last  century,  Vicentius  Menghini  published 
in  the  Transactions  of  the  Academy  of  Sciences  of 
Bologna,  an  account  of  experiments  which  contri- 
buted to  establish  this  sentiment.  In  this  account 
he  stated,  that,  after  washing  the  colouring  matter 
from  the  crassamentum,  he  had  separated  it  from  the 
water  by  boiling;  in  which  case  it  either  rose  to  the 
surface  of  the  water,  or  subsided,  and  left  the  water 
clear.  After  drying,  with  a gentle  heat,  some  of 
the  colouring  matter  thus  separated,  and  then  re- 
peatedly washing  it,  he  found  that  it  contained  a 
considerable  quantity  of  iron,  which  was  attracted  by 
the  magnet. 

After  exposing  a large  quantity  of  the  colouring 
matter  to  an  intense  heat,  he  found  in  it  a small 
piece  of  iron,  of  a spherical  form,  but  hollow;  and 
a powder  which  was  attracted  by  the  magnet,  but  ap- 
peared more  like  rust  of  iron  than  iron  filings. 

He  believes  the  seat  of  this  iron  to  be  in  the  co- 
louring matter  of  the  blood,  as  neither  the  serum  nor 
fibrine  appeared  to  contain  it.  According  to  his  cal- 
culation, the  blood  of  a healthy  man  contains  more 
than  two  ounces  of  iron. 

This  doctrine  of  Menghini  has  been  very  gene- 
rally admitted ; and  several  ehemists  of  the  first 
character,  viz.  Bucquet,  Foureroy,  Vauquelin,  &c. 


407 


Appendix .* — Of  the  Blood. 

have  made  experiments  to  ascertain  the  substances 
with  which  the  iron  in  the  blood  is  combined. 

But  within  a few  years,  doubts  have  been  express- 
ed on  this  subject  by  several  physiologists,  and  espe- 
cially by  Dr.  Wells,  and  Mr.  Brande. 

The  first  of  these  gentlemen,  in  his  “ Observations 
and  Experiments  on  the  Colour  of  the  Blood”  pub- 
lished in  the  London  Philosophical  Transactions  for 
1797,  states  three  reasons  for  rejecting  the  opinion 
that  the  colour  of  the  blood  is  derived  from  iron. 

1.  The  colour  of  blood  is  destroyed  by  a heat  less 
than  that  of  boiling  water;  whereas  no  colour  arising 
from  a metal  is  destroyed  by  exposing  its  subject,  in 
a close  vessel,  to  such  a heat. 

2.  If  the  colour  from  a metal,  in  any  substance,  be 
destroyed  by  any  alkali,  it  may  be  restored  by  the 
immediate  addition  of  an  acid;  and  the  like  will 
happen  by  the  addition  of  a proper  quantity  of  an  al- 
kali,  if  the  colour  has  been  destroyed  by  an  acid.— 
The  colour  of  blood,  on  the  contrary,  when  once  de- 
stroyed, can  never  be  brought  back,  either  by  an 
acid  or  an  alkali. 

3.  If  iron  be  the  cause  of  the  red  colour  of  blood, 
it  must  exist  there  in  a saline  state ; since  the  red 
matter  is  soluble  in  water.  The  substances,  there- 
fore, which  detect  the  smallest  quantity  of  iron  in 
such  a state,  ought  likewise  to  demonstrate  its  pre- 
sence in  blood;  but  upon  adding  Prussian  alkali, 
and  an  infusion  of  galls,  to  a very  saturated  solution 
of  the  red  matter,  he  could  not  observe  “in  the  form- 
er case  the  slightest  blue  precipitate;  or  in  the  latter 
that  the  mixture  had  acquired  the  least  blue  or  pur- 
ple tint.” 

Mr.  Brande,  in  a paper  entitled  “ Chemical  Re- 
searches on  the  Blood”  &e.  communicated  to  the 
Royal  Society  of  London  in  1812,  relates  many  ex- 
periments which  were  made  on  the  colouring  matter 


408  Appendix. —Structure  of  the  Glands . 

of  that  fluid,  with  acids,  alkalies,  astringents,  &c.  &e. 
From  these  experiments,  he  also  infers,  that  the  co- 
louring matter  of  the  blood  is  perfectly  independent 
of  iron . 

In  support  of  this  inference,  he  adds,  that  the  Ar- 
menian dyers,  in  the  preparation  of  their  finest  and 
most  durable  red  colours,  use  blood  in  addition  to 
madder,  in  order  to  ensure  the  permanency  of  these 
colours.  As  the  compounds  of  iron  convert  the  co- 
lour of  madder  to  gray  and  black,  the  production  of 
a bright  colour  by  the  addition  of  blood  to  madder, 
he  regards  as  a proof,  that  iron  is  not  the  colouring 
matter  of  blood. 

Many  estimates  have  been  made  of  the  quantity 
of  blood  in  the  human  body;  but  some  of  the  best  in- 
formed physiologists  have  regarded  them  as  falla- 
cious. 


STRUCTURE  OF  GLANDS. 

Any  original  structure  that  discharges  from  the 
blood  vessels  a fluid  different  from  those  which  they 
naturally  contain,  may  be  considered  as  glandular. 
The  function  or  process  by  which  such  fluids  are  de- 
rived from  the  blood  vessels  is  called  secretion. 

A structure  of  this  kind  seems  to  exist  in  very  dif- 
ferent situations:  for  it  is  distinctly  circumscribed  in 
many  of  those  bodies  commonly  denominated  glands, 
which  are  of  a very  precise  form ; and  it  is  also  dif- 
fused on  some  very  extensive  surfaces.  The  gastric 
liquor,  a most  important  secretion,  is  probably  dis- 
charged from  vessels  which  open,  like  exhalents,  on 
the  internal  surface  of  the  stomach;  and  not  from  any 
circumscribed  bodies,  which  are  generally  denomi- 
nated glands. 

The  name  of  gland  is  theoretically  applied  to 


409 


Appendix.— -Structure  of  Glands . 

several  bodies  which  cannot  be  proved  to  secrete 
any  fluid  whatever  ; and  also  to  those  bodies  con- 
nected with  the  absorbent  vessels,  which  are  called 
the  Lymphatic  Glands  ; but  it  is  most  commonly  ap- 
propriated to  those  organs  which  discharge  a fluid 
different  from  the  blood. 

The  structure  by  which  mucus  is  secreted  in  some 
places,  appears  to  be  very  simple.  Thus  in  the 
Schneiderian  membrane  and  the  urethra,  there  are 
small  ducts  from  four  to  six  lines  in  length,  and 
equal  in  diameter  to  a bristle,  which  appear  to  be 
formed  of  the  membrane  on  which  they  open.  From 
these  ducts  mucus  issues  to  cover  the  surfaces  of 
these  membranes.  In  many  instances  there  is  no 
substance  resembling  that  of  the  circumscribed  glan- 
dular bodies,  connected  with  these  ducts;  but  the 
secreted  fluid  seems  to  be  discharged  into  the  ducts 
from  the  small  vessels  on  their  surfaces.  The  ducts 
of  this  nature  in  the  urethra  are  denominated  La - 
cunse. 

In  some  other  parts  of  the  body,  the  cavities  into 
which  mucus  is  discharged  are  somewhat  different, 
both  in  form  and  size,  from  those  above  mentioned, 
and  are  called  Follicles.  These  cavities  are  sur- 
rounded with  more  or  less  of  a pulpy  vascular  sub- 
stance, which  has  been  considered  as  glandular,  and 
essential  to  the  mucous  secretion. 

The  circumscribed  bodies,  which  are  commonly 
called  glands,  differ  in  their  internal  appearance  and 
texture,  from  the  other  parts  of  animals.  The  sub- 
stance of  which  they  consist  differs  very  much  in  the 
different  glands;  and  thus  renders  the  liver,  kid- 
neys, salivary  glands,  mammae,  &c.  very  different 
from  each  other.  Some  glands,  as  the  salivary,  &c„ 
are  composed  of  several  series  of  lobuli  that  succes- 
sively diminish.  The  smallest  of  these  are  denomi- 
nated Acini.  Each  of  them  is  connected  by  a 

Vol.  ii.  52 


410  Appendix. — Structure  of  Glands. 

small  artery  and  vein,  to  the  large  blood  vessels  of 
the  glands  ; and  also  sends  a hranch  to  join  the  ex- 
cretory duct.  These  Acini  are  therefore  connected 
to  each  other,  by  the  blood  vessels  and  excretory 
duct  of  the  gland,  and  also  by  the  cellular  membrane, 
which  cuvers  them  externally,  and  occasions  them  to 
adhere  to  each  other  where  they  are  in  contact.  In 
consequence  of  this  structure,  these  glands  have  a 
granulated  appearance. 

The  liver,  when  incised  with  a sharp  instrument, 
appears  differently ; but  when  broken  into  pieces,  it 
seems  to  consist  of  small  acini.  Some  other  glands, 
as  the  Prostate , appear  to  be  uniform  in  their  tex- 
ture, and  have  none  of  this  granulated  appearance. 

The  structure  of  glands  has  long  been  an  interest- 
ing object  of  anatomical  inquiry,  and  was  investiga- 
ted with  great  assiduity  by  those  eminent  anatomists, 
Malpighi  and  Ruysch. 

Malpighi,  as  was  formerly  observed,  used  ink  and 
other  coloured  fluids  in  his  injections.  He  was  also 
very  skilful  in  the  use  of  microscopes,  and  took  great 
pains  in  macerating  and  preparing  the  subjects  of  his 
inquiries.  Ruysch,  on  the  other  hand,  used  a ce- 
raceous  injection,  and  was  most  eminently  successful 
in  filling  very  small  vessels  with  it.  Malpighi  be- 
lieved that  there  were  follicles  or  cavities  in  glandu- 
lar bodies,  which  existed  between  the  extremities  of 
the  arteries  and  the  commencement  of  the  excretory 
ducts  of  those  bodies,  and  that  in  these  cavities  the 
secreted  fluids  underwent  a change. — Ruysch  con- 
tended, that  the  arteries  of  glands  were  continued 
into  excretory  ducts,  without  the  intervention  of 
any  cavity  or  follicle  ; that  the  small  bodies,  which 
had  been  supposed  to  contain  follicles  or  cripae,  were 
formed  by  convulsions  of  vessels,  and  that  the  change 
of  the  fluid,  or  the  process  of  secretion,  is  produced 
by  the  minute  ramifications  of  the  artery. 


Appendix. — Structure  of  Glands.  411 

A very  interesting  account  of  this  subject  is  con- 
tained in  two  celebrated  letters,  which  passed  be- 
tween Boerhaave  and  Ruysch  in  the  year  1721,  and 
are  published  at  the  end  of  the  fourth  volume  of  the 
works  of  Ruysch. 

The  opinion  of  Ruysch  has  been  most  generally 
adopted  by  anatomists,  and  has  derived  support  and 
confirmation  from  several  anatomists  since  his  time. 
The  late  Mr.  Hewson  declared  his  conviction  that 
the  small  globular  bodies  which  are  scattered  through 
the  kidneys,  and  were  supposed  to  be  follicles  or 
criptse,  are  merely  convoluted  arteries.  He  also  as- 
serted, that  the  acini  which  appeared  in  the  mammae 
as  large  as  the  heads  of  pins,  when  the  excretory 
ducts  of  that  gland  were  injected  with  vermilion  and 
painters’  size,  proved  to  be  the  minute  ramifications 
of  the  excretory  duct,  which  divided  very  suddenly 
into  branches  so  small,  that  they  could  not  readily  be 
seen  by  the  naked  eye.* 

Notwithstanding  these  reasons  for  supposing  that 
the  excretory  ducts  of  glands  were  derived  simply 
from  the  arteries  of  those  bodies,  it  is  said  that  the 
late  Dr.  W.  Hunter  used  to  declare  his  belief,  that 
there  was  a part  in  glands  which  was  not  injected,  in 
his  preparations ; and  to  say  further,  that  he  believed 
his  preparations  were  injected  as  minutely  as  those 
of  Ruysch. 

All  of  these  opinions  have  been  strenuously  con- 
troverted by  the  Italian  anatomist,  Mascagni,  who 
believes  that  the  arteries  terminate  only  in  veins  : 
and.  of  course  that  they  neither  form  exhalent  ves- 
sels, nor  communicate  with  the  excretory  ducts  of 
glands.  His  idea  of  the  structure  of  glands  is  dif- 
ferent from  those  either  of  Malpighi  or  of  Ruysch, 


* See  Experimental  Inquiries,  vol.  ii.  p.  178. 


412  Appendix . — Structure  of  Glands. 

He  supposes  that  glands  contain  a great  number  of 
minute  cells ; that  the  arteries,  veins,  and  absorbent 
vessels  are  spread  upon  the  surfaces  of  these  cells, 
in  great  numbers,  and  very  irregularly.  From  these 
cells  very  small  canals  originate,  which  unite  to 
form  the  small  branches  of  the  excretory  ducts. — 
According  to  his  idea  the  secreted  fluid  is  dis- 
charged through  pores  or  orifices  of  the  blood  ves- 
sels, into  the  cells,  and  proceeds  from  them  through 
the  canals,  into  the  branches  of  the  excretory  ducts. 
Absorbent  vessels,  in  great  numbers,  originate  from 
these  cells. 

In  his  great  work  on  the  absorbent  system,  when 
treating  on  the  termination  of  arteries  and  the  com- 
mencement of  veins,  (Part  I.  Section  2.)  he  asserts, 
that  if  the  kidneys  are  successfully  injected  with 
size,  coloured  with  vermilion,  and  then  laid  open  by 
a section  with  a razor,  it  will  be  found  that  the  size 
without  the  colour  has  passed  into  cells,  which  are 
very  numerous  ; that  the  arteries  and  veins  are  ra- 
ramified  most  minutely  on  the  surfaces  of  these  cells, 
and  that  the  tubuli  uriniferi,  as  well  as  the  absorbent 
vessels,  originate  from  them. 

He  supposes  that  a considerable  portion  of  the  fluid 
thus  passing  off  from  the  blood  vessels,  is  commonly 
taken  up  by  the  absorbent  vessels  of  the  kidneys;  for 
in  two  cases  in  which  he  found  the  absorbent  vessels 
obstructed,  a diabetes  existed,  which  he  considered 
as  the  effect  of  the  inactivity  of  the  absorbents.  He 
asserts,  that  in  the  liver,  pancreas,  mammas,  and  also 
in  the  salivary  and  lachrymal  glands,  the  minute  ar- 
teries and  veins  are  also  distributed  upon  the  surfaces 
of  cells  ; and  that  very  small  canals  arise  from  these 
cells,  and  unite  to  form  the  small  branches  of  the  ex- 
cretory ducts. 

This  great  anatomist  appears  to  have  been  much 


Appendix.— Structure  of  Glands.  413 

occupied  with  microscopical  observations,  and  has 
gone  largely  into  the  discussion  of  this  subject.* 

It  must,  however,  be  acknowledged,  that  no  information 
which  has  as  yet  been  obtained  respecting  the  struc- 
ture of  glands,  enables  us  to  explain  their  wonder- 
ful effect  upon  the  fluids  which  pass  through  them. 
It  remains  yet  to  be  ascertained  why  one  structure 
forms  saliva  and  another  bile  ; or  why  so  much  ap- 
paratus should  be  necessary  for  the  s.ecretion  of 
milk,  when  adiopose  matter  appears  to  be  produced 
by  the  mere  membi-ane  in  which  it  is  contained. 

Dr.  Berzelius,  professor  of  Chemistry  at  Stockholm, 
in  a late  work  on  animal  chemistry,  asserts,  that 
if  all  the  nerves  going  to  a secretory  organ  are  di- 
vided, secretion  will  cease,  notwithstanding  the 
continued  circulation  of  the  blood.  From  this,  he 
thinks,  that  secretions  depend  upon  the  influence  of 
nerves,  although  he  cannot  explain  their  effects. 

Mr.  Home,  after  relating  some  experiments  upon 
blood  and  serum,  made  with  the  Voltaic  Battery, 
proposes  the  following  questions,  among  others : — - 
Whether  a weaker  power  of  electricity  than  any 
which  can  be  kept  up  by  art,  may  be  capable  of  se- 
parating from  the  blood  the  different  parts  of  which 
it  is  composed  ; and  forming  new  combinations  of 
the  parts  so  separated  ? — Whether  the  structure  of 
the  nerves  may  enable  them  to  possess  a low  elec- 
trical power,  which  can  be  employed  for  that  pur- 
pose ? &c. 

See  the  London  Philosophical  Transactions,  for 
1809,  Part  ll.t 

* The  late  Dr.  W.  Hunter,  in  his  Medical  Commentaries,  (p.  40,)  avowed 
his  belief,  that  the  fluids,  which  appear  occasionally  in  the  various  cavi- 
ties of  the  body,  transude  through  the  coats  of  the  blood  vessels.  Mr. 
Hewson,  (Experimental  Inquiries,  Vol.  II.  Chap.  7.)  suggested  several 
reasons  for  dissenting  from  this  opinion;  but  Mascagni  has  endeavoured  to 
support  it. — See  a long  note  to  the  above  mentioned  section  of  his  work, 
page  74. 

t Mr.  Wollasion  has  also  published  a small  paper  on  this  subject  in  the 
Philosophical  Magazine,  Vol.  33. 


GLOSSARY, 


EXHIBITING  THE  DERIVATION  OF  CERTAIN  ANATOMICAL 
TERMS. 


A. 

ACETABULUM.  The  cavity  which  receives  the  head  of 
the  thigh-bone  ; from  acetum  vinegar  : so  called,  because 
it  represents  the  acetabulum  or  saucer  of  the  ancients,  in 
which  vinegar  was  held  for  the  use  of  the  table. 

Acini.  From  acinus  a grape. 

Acromion.  A process  of  the  scapula ; from  ay,po 5 extremity, 
and  1 vpes  the  shoulder. 

Anastomosis.  The  communication  of  vessels  with  one  ano- 
ther; from  ctva  through,  and  rajtt*  mouth. 

Anatomy.  The  dissection  of  the  human  body ; from  kvk,  and 
rs/itvo  to  dissect. 

Anconeus . A muscle  ; so  called  from  ctynav  the  elbow. 

Aorta.  Aoprsj  from  ; a?,o  air,  and  r-^eoj  to  keep. 

Aponeurosis.  A tendinous  expansion  ; from  Karo,  and  vsvpev  a 
nerve ; from  an  erroneous  supposition  of  the  ancients,  that 
it  was  formed  by  an  expansion  of  nerve. 

Apophysis.  A process  of  a bone  ; from  ct7n><pva  to  proceed 
from.  A synonyme  of  process. 

Arachnoides.  A net-like  membrane  ; from  apayjn  a spider, 
and  s 1^05  likeness. 

Artery.  From  *-0?  air,  and  r to  keep ; because  the  ancients 
supposed  that  air  only  was  contained  in  them. 

Arthrodia.  A species  of  connexion  of  bones ; from  ctpSpoa  to 
articulate. 

Arytsenoides.  The  name  of  two  cartilages  of  the  larynx ; also 
applied  to  some  muscles  of  the  larynx ; from  ctpvTxi'nt  a 
funnel,  and  sifas  a shape. 


By  Dr.  Hooper. 


416  Glossary . 

Astragalus.  A bone  of  the  tarsus  ; so  called  from  its  resem- 
blance to  a die  used  in  ancient  games,  from  a 

cockal  or  dje. 

Atlas.  The  first  vertebra  of  the  neck  ; so  called,  because  it 
sustains  the  head  : from  the  fable  of  Atlas  being  supposed 
to  have  supported  the  world;  or  from  to  sustain,  be- 

cause it  sustains  the  head. 

Azygos.  A term  applied  to  parts  without  a fellow,  from  « 
priv.  and  ^yo?  a joke,  because  it  has  no  fellow. 


B. 

Bursa.  A bag ; from  /3 vpnx, : generally  applied  to  the  bursae 
mucosae. 

C. 

Cancelli.  Lattice  work  ; generally  applied  to  the  reticular 
substance  in  bones. 

Cardia.  The  superior  opening  of  the  stomach  ; from  x»p, het 
the  heart. 

Carotid.  The  name  of  some  arteries  of  the  neck  and  head 
from  xetpoo)  to  cause  to  sleep  ; for,  if  tied  with  a ligature, 
the  animal  was  said  to  be  affected  with  coma. 

Carpus.  Kctpnos  ; the  wrist. 

Clavicula.  The  clavicle  or  collar-bone,  a diminutive  of  clavis 
a key;  so  called  from  its  resemblance  to  an  ancient  key. 

Clinoid.  Four  processes  of  the  sella  turcica  of  the  ethmoid 
bone  are  so  called,  from  a bed,  and  e«5as  likeness ; 
from  their  supposed  resemblance  to  a couch. 

Clitoris.  A part  of  the  female  pudenda  ; enclosed  by  the  la- 
bia majora  ; from  xXeicu  to  enclose  or  hide. 

Colon.  The  first  of  the  large  intestines  ; from  xoiMv,  quasi 
jco/Aov,  from  xoiM 5 hollow. 

Coracoid.  From  a crow,  and  eiS'op  resemblance  ; shaped 
like  the  beak  of  a crow. 

Coronary.  From  corona  a crown.  The  vessels  of  the  heart, 
stomach,  &c.  are  so  called  because  they  surround  the  parts 
in  the  manner  of  a crown. 

Cotyloid.  From  MtvXv,  the  name  of  an  old  measure,  and  a fop 
resemblance  : resembling  the  kotule. 

Cranium.  The  skull ; xpeeviav, quasi,  Kecpcauev,  from  xuptx.  the  head. 

Cremaster.  A muscle  so  called  ; from  to  suspend,  be- 

cause it  suspends  the  testicle. 

Cribriform.  From  cribmm  a sieve,  it  being  perforated  like  a 
sieve. 


Glossary.  417 

Cricoid.  Annular,  round  like  a ring;  from  y^Uo 5 a ring  and 
£<&>$  likeness. 

Cuboides.  A bone  of  the  foot ; from  a cube,  and  enJ'uj 
likeness  ; because  it  resembles  a cube. 

Cuneiform.  Some  bones  are  so  called  ; from  cuneus  a wedge, 
and  forma  likeness  ; being  shaped  like  a wedge. 

D. 

Deltoid.  A muscle  resembling  the  Greek  letter  A : from  A, 
and  eih 5 resemblance. 

Diaphragm.  The  muscle  which  separates  the  thorax  from  the 
abdomen  ; from  to  divide. 

Diarthrosis.  A moveable  connexion  of  bones;  from f$icto6goa 
to  articulate. 

Digastric.  From  <5Vs  twice,  and  ng  a bell y ; having  two 
bellies. 

Diploe.  The  spongy  substance  between  the  two  tables  of  the 
skull  ; from  fttrXttt  to  double. 

Duodenum.  The  first  portion  of  the  small  intestines ; so  call- 
ed because  the  ancients  supposed  that  it  did  not  exceed 
the  breadth  of  twelve  fingers  ; from.  duodenUs,  consisting 
of  twelve. 

Dura  Mater.  The  outermost  membrane  of  the  brain  ; called 
dura , because  it  is  much  harder  than  the  other  membranes, 
and  mater , from  the  idea  of  the  ancient^  that  it  was  the 
source  of  all  the  other  membranes. 

E. 

Embryo.  The  child  in  the  womb  is  so  called  before  the  fifth 
month,  after  which  it  is  termed  foetus  ; from  e^v&>  to  bud 
forth. 

Enarthrosis.  An  articulation  of  bones  ; from  -a  in,  and 
a joint  or  articulation. 

Enteric.  Belonging  to  the  intestines  ; from  evregov  an  entrail 
or  intestine. 

Epidermis.  The  scarf  or  outermost  skin ; from  tm  upon,  and 
thg/tii  the  skin.  . .. 

Epididymis.  The  small  oblong  body  which  lies  above  the  tes- 
ticles ; from  upon,  and  JiS'v/. a testicle. 

Epigastric.  The  superior  part  of  the  abdomen ; from  svt 
upon,  and  the  stomach. 

Epiglottis , A cartilage  of  the  larynx  so  called;  from  em  upon, 
and  yxarhi  the  aperture  of  the  larynx,  being  situated  upon 
the  glottis. 

VOL,  II.  53 


418  Glossary. 

Epiphysis , A portion  of  bone  growing  upon  another  bone,  but 
separated  from  it  by  a cartilage  : from  em  upon,  and  pva 
to  grow. 

Epiploor i.  The  membranous  viscusof  the  abdomen,  which  co- 
vers the  intestines,  and  hangs  to  the  bottom  of  the  stomach; 
from  eKin-Xsa  to  swim  upon. 

Ethmoid.  From  a sieve,  and  e/^05  resemblance;  being 
perforated  like  a sieve. 

F. 

Fascia.  An  expansion,  enclosing  other  parts,  like  a band  ; 
from  fascis  a bundle. 

Falciform.  Shaped  like  a si  the ; from  falx,  a si  the. 

Fasciculus.  A little  bundle,  dim.  of  fascis  a bundle. 

Fauces.  The  plural  of  faux , the  top  of  the  throat. 

G. 

Ganglion.  Tv/y^iot,  a knot  in  the  course  of  a nerve. 

Gastrocnemius.  The  muscle  which  forms  the  thick  of  the  leg; 
from  a belly,  and  the  leg. 

Genio.  Names  compounded  with  this  word  belong  to  mus- 
cles which  are  attached  to  the  chin,  as  geno-glossus — geno- 
hyoideus,  &c. ; from  yeve;ov  the  chin. 

Ginglymus.  An  articulation  ; from  yifyXv^ot;  a hinge. 

Glenoid  cavity.  From  y*m  a cavity,  and  a Sat  resemblance. 

Glosso.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  tongue  ; as  glosso-pharyngeus — 
glosso-staphilinus,  &c. ; from  yXawu,  the  tongue. 

Glottis.  The  superior  opening  of  the  larynx  at  the  bottom  of 
the  tongue  ; from  yXcaria  the  tongue. 

Glutseus.  The  name  of  a muscle  ; from  yA&rog  the  buttocks. 

Gomphosis.  To^paicng,  a species  of  immoveable  connexion  of 
bones ; from  yo/tnpet  a nail,  because  one  bone  is  fixed  in  an- 
other bone  like  a nail  in  a board. 

II.  , 

Helix.  The  outward  circle  of  the  ear;  from  uXta  to  turn  about. 

Hepar.  The  liver.  an  abdominal  viscus. 

Hyaloid.  From  glass,  and  uS 'as  likeness ; the  capsule  of 
the  vitreous  humour  of  the  eye  is  so  called,  from  its  trans- 
parent and  glassy  appearance. 

Hymen.  The  membrane  situated  at  the  entrance  of  the  vir- 
gin vagina  ; from  Hymen,  the  god  of  marriage. 

Hyoides.  A bone  of  the,  tongue,  so  called  from  its  resem- 
blance to  the  Greek  v ; from  v,  and  resemblance. 


419 


Glossary. 

Hypochondrium.  That  part  of  the  body  which  lies  under  the 
cartilages  of  the  spurious  ribs  ; from  uxa  under,  and 
a cartilage.  ! 

Hypogastric.  The  lower  region  of  the  fore  part  of  the  abdo- 
men ; from  v7ro  under,  and  y« the  stomach. 

I. 

lleon.  A portion  of  the  small  intestines  ; from  uXea  to  turn  ; 
being  always  convoluted. 

Ischium.  The  part  of  the  os  innominatum  upon  which  we  sit; 
from  nr%va  to  sustain. 

L. 

Lacuna.  The  excretory  duct  of  the  glands  of  the  urethra  and 
vagina  ; from  lacus  a channel. 

Lambdoidal  suture.  So  called  because  it  is  shaped  like  the 
letter  A ; from  A,  and  etfos  resemblance. 

Larynx.  The  superior  part  of  the  windpipe;  the  larynx. 

, M. 

Masseter.  A muscle  of  the  face,  which  assists  in  the  action 
of  chewing;  paro-cupai  to  chew. 

Mastoid.  From  yM?o<i  a teat,  and  ei^og  likeness ; shaped  like  a 
nipple  or  teat. 

Mediastinum.  The  production  of  the  pleura,  which  divides 
the  thorax  into  two  cavities  ; from  medium  the  middle, 
quasi  in  medio  stare. 

Mesentery.  The  membranes  to  which  the  intestines  are  at- 
tached ; from  pto-o 5 the  middle,  and  enr^ov  an  intestine,  be- 
cause it  is  in  the  middle  of  the  intestines. 

Mesocolon.  That  part  of  the  mesentery  in  the  middle  of  the 
colon ; from  the  middle,  and  koA«v  the  colon. 

Metacarpus.  1 hat  part  of  the  hand  between  the  carpus  and 
lingers  ; from  yera.  after,  and  nagnoi  the  wrist. 

Metatarsus.  I hat  part  ot  the  foot  between  the  tarsus  and 
toes ; from  y.sra  after,  and  the  tarsus. 

Mylo.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  near  the  grinders,  as  mylo-hyoideus, 
&c. ; from  a grinder  tooth. 

0. 

Odontoid.  Tooth-like;  from  oS'm  a tooth,  and  ufos  resemblance. 

(Esophagus.  The  canal  leading  from  the  pharynx  to  the  sto- 
mach ; from  ota  to  carry,  and  tyaya  to  eat ; because  it  car- 
ries the  food  into  the  stomach. 


420 


Glossary . 

Olecranon.  The  elbow,  or  bead  of  the  ulna;  from  &)Xm  the 
cubit*  and  *£«vov  the  head. 

Omentum.  An  abdominal  viscus;  so  called  from  omen  a guess, 
because  the  soothsayers  prophesied  from  the  inspection  of 
this  part. 

Omo.  Names  compounded  with  this  word  belong  to  muscles 
which  are  attached  to  the  scapula,  as  omo-hyoideus , &c. 
from  aw  the  shoulder. 

Omojjlata.  The  scapula  or  shoulder  blade ; from  apos  the 
shoulder,  and  vxwrvs  broad. 

Osteology.  The  doctrine  of  the  bones;  from  «!■£«  a bone,  and 
Aioy®s  a discourse. 

P. 

Pancreas.  A viscus  of  the  abdomen ; so  called  from  its  fleshy 
consistence;  from  nav  all,  and  flesh. 

Parenchyma.  The  substance  of  some  of  the  viscera  was  so 
called,  from  Trageytcva  to  pour  through. 

Parotid  Gland.  From  near,  and  <ws  the  ear;  because  it 
is  situated  near  the  ear. 

Pelvis.  A bony  cavity  shaped  like  a basin;  from  veXv<;  a basin. 

Pericardium.  The  membrane  which  surrounds  the  heart; 
from  Trefi  around,  and  x.xgS'tx  the  heart. 

Pericranium.  The  membrane  which  covers  the  bones  of  the 
skull ; from  7rigt  around,  and  xf«v£«v  the  cranium  or  head. 

Periosteum.  The  membrane  which  surrounds  the  bones;  from 
around,  and  es-eov  a bone. 

Peristaltic  motion  of  the  intestines;  from  Tegus-xx a to  contract. 

Peritoneum.  The  membrane  lining- the  abdomen,  and  cover- 
ing its  viscera;  from  to  extend  around. 

Phalanx.  The  bones  of  the  fingers  and  toes  are  called  pha- 
lanxes, from  their  regular  situation,  like  a <px,Xouy^,  or  ar- 
rangement of  soldiers. 

Pharynx.  A membranous  bag  at  the  end  of  the  mouth  ; 
t«  because  it  conveys  the  food  into  the  stomach. 

Phrenic  or  diaphragmatic  nerve.  <%eves  the  diaphragm  ; from 
sjv  the  mind  ; because  the  ancients  supposed  it  to  be  the 
seat  of  the  mind. 

Pia  Mater.  The  innermost  membrane  of  the  brain,  so  called 
because  it  embraces  the  brain  as  a careful  mother  folds  her 
child. 

Pleura.  The  membrane  lining  the  thorax  ; nx evga  the  side. 

Plexus.  A kind  of  net-work  of  vessels  or  nerves;  from  plecto 
to  weave  together. 


Glossary.  421 

Psoas.  A muscle  so  called  ; from  fyoa,  the  loin,  being  situa- 
ted in  the  loins. 

Pterygoid  process.  From  v%  a pen  or  wing,  and  erfo  s like- 
ness, so  called  from  its  likeness  to  a pen  or  wing. 

Pylorus.  The  lower  orifice  of  the  stomach,  which  opens  into 
the  intestines;  from  •TrvXow  to  guard  an  entrance,  because 
it  guards  as  it  were  the  entrance  of  the  bowels. 

R. 

Raphe.  A suture  ; from  pair] a to  sew. 

Rcnes.  The  kidneys,  a no  m petv,  because  through  tliem  the 
urine  flows. 

Retina.  The  net-like  expansion  of  the  optic  nerve,  on  the 
inner  surface  of  the  eye;  from  rete  a net. 

Rkomboides.  A muscle  so  called  from  its  shape;  from  pou.Sog7 
a geometrical  figure,  whose  sides  are  equal  but  not  right- 
angled,  and  e«Jo;  a likeness. 

Rotula.  The  knee-pan;  a dim.  of  rota  a wheel,  from  its  shape. 

S. 

Sacrum.  A bone  so  called  ; from  sacer  sacred,  because  it  was 
once  offered  in  sacrifices. 

Salvatella.  A vein  of  the  foot,  so  called  because  it  was  thought 
that  opening  it  preserved  health,  and  cured  melancholy; 
from  salvo  to  preserve. 

Sanguis.  The  biood  ; avo  tx  -onn  yyi*.  because  it  preserves 
the  body. 

Sartorius.  A muscle  so  called,  because  tailors  cross  their  legs 
with  it ; from  sartor  a tailor. 

Scupha.  The  depression  of  the  outer  ear  before  the  anti-he- 
lix; from  o-kx^i  a little  boat  or  skill’. 

Scaphoides.  A bone  of  the  carpus,  so  called  from  its  resem- 
blance to  a skiff';  from  a skiff,  and  eth 5 likeness. 

Sclerotic.  A term  applied  to  the  outermost  or  hardest  mem- 
brane of  the  eye  ; from  m^goca  to  make  hard. 

Sesamoid  bones.  From  o-yrxf. ty  a grain,  and  Jo?  likeness  ; 
from  their  resemblance  to  the  semen  sesami. 

Sigmoid.  Parts  are  so  called  from  their  resemblance  to  the 
letter  £;  from  2,  the  letter  Sigma,  and  likeness. 

Sphenoid.  From  jv  a wedge,  and  etfo 5 likeness  ; shaped  like 
a wedge. 

Sphincter.  The  name  of  several  muscles,  whose  office  is  to 
shut  up  the  aperture  around  which  they  are  placed  from  ; 
tnpryyoi  to  shut  up. 

Splanchnic.  From  e-^Aseyj^va;,  an  entrail. 


422  Glossary. 

Symphysis.  A connexion  of  bones  ; from  rv^cpva  to  grow  to- 
gether. 

Synarthrosis.  A connexion  of  bones;  from  rm  with,  and  xpipov 
a joint. 

Synchondrosis.  A species  of  union  of  bones  by  means  of  car- 
tilage ; from  c-t/v  with,  and  ■ ^ov^og  a cartilage. 

Synneurosis.  A species  of  connexion  of  bones  by  means  of 
membrane  ; from  < ruv  with,  and  vfi^ag  a nerve;  because  mem- 
branes, ligaments,  and  tendons,  were  by  the  ancients  con- 
sidered as  nerves. 

Syssarcosis.  A species  of  connexion  of  bones  by  means  of 
muscle ; from  o-w  with,  and  flesh. 

Systole.  The  contractile  motion  of  the  heart  and  arteries;  from 
crys-rfMa  to  contract. 

,T. 

Tendon , From  ■mv&>  to,  extend. 

Thorax.  The  breast  or  chest. 

Thyroid.  From  Stress  a shield,  and  uctog  likeness;  shaped  like 
a shield. 

Trachea.  The  windpipe  ; so  called  from  its  roughness  ; from 
TQv.yju',  rough. 

Trochanter.  A process  of  the  thigh-bone,  so  called  from  r^oyag 
a wheel. 

U. 

Ulna.  A name  for  the  cubit ; from  aXew  the  cubit. 

Ureter.  The  canal  which  conveys  the  urine  from  the  kidney 
to  the  bladder;  from  xgov  urine. 

Urethra.  The  passage  through  which  the  urine  passes  from 
the  bladder  ; from  the  urine. 

Uvea.  The  posterior  lamen  of  the  iris,  so  called  because  in 
many  animals  it  is  of  the  colour  of  unripe  grapes  ; from 
uva  an  unripe  grape. 

Uvula.  The  conical  substance  which  hangs  down  from  the 
middle  of  the  soft  palate  : so  called  from  its  resemblance 
to  a grape.  A dim.  of  uva  a grape. 

y. 

Valves.  From  valvse  folding  doors. 

Vertebrae.  The  bones  of  the  spine  are  so  called  ; from  verto 
to  turn. 

X. 

Xiphoid.  So  called  from  the  resemblance  to  a sword  ; from 
| i<ptS  a sword,  and  si^og  likeness. 

Z. 

Zygoma.  The  cavity  under  the  zygomatic  process  of  the 
temporal  bones  ; from  <V/«s  a yoke. 


ALPHABETICAL  INDEX  TO  VOLUME  II. 


Aorta 

Page. 
50  and  236 

Adhesion  of  lungs 

73 

Abdomen 

82 

regions  of 

86 

contents  of 

85 

situation  of  vis- 

cera 

87 

Acini  of  liver 

132 

Arteries, 

structure  of 

226 

Artery,  axillary 

262 

aorta  thoracic 

270 

abdominal 

274 

adipose 

281 

anastomotic 

292 

anterior  tibial 

294 

basilic 

259 

bronchial 

270 

carotid 

239 

external 

240 

internal 

250 

callous 

256 

cervical 

261 

circumflex 

564 

cceliac 

275 

capsular 

280 

circumflex  of 

ilium 

289 

of  thigh  291 

emulgent 

280 

epigastric 

288 

facial 

242 

femorial 

289 

gastric 

2 75 

right 

276 

left 

277 

gluteal 

286 

humeral 

264 

hepatic 

276 

haemorrhoidal 

285 

innominata 

238 

Page, 

Artery, internal  maxillary  245 
mammary  257 
intercostals  supe- 


rior 

260 

interosseal 

267 

intercostals  infe- 

rior 

272 

illiac  primitive 

282 

internal 

283 

ilio  lumbar 

284 

iliac  external 

288 

internal  plantar 

296 

ischiatic 

286 

lingual 

242 

lumbar 

282 

middle  of  brain 

255 

mammary  exter- 

nal 

262 

mesenteric  supe- 

rior 

278 

infe- 

rior 

279 

occi- 

pital 

244 

ophthalmic 

252 

oesophageal 

271 

obturator 

285 

pharyngeal  infe- 

rior 

'243 

phrenic 

274 

pudic  internal 

287 

external 

290 

profunda  femoris  290 
perforating  291 
popliteal  292 

posterior  tibial  295 
peroneal  295 

plantar  external  296 
radial  266 

stylo-mastoid  245 


INDEX. 


424 

Artery,  subclavian  256 

scapular  superior  260 

internal  263 

spiral  265 

splenic  27  7 

spermatic  28 1 

sacral  middle  282 

lateral  284 

thyroid  superior  241 

inferior  258 

temporal  249 

ulnar  268 

uterine  286 

vertebral  258 

Arterial  system,  plan  of  297 

Abdominal  viscera,  nerves 
of  368 

Absorbents,  structure  of  371 

of  lower  ex- 
tremity 37fi 

of  abdomen  381 

of  thorax  389 

of  head  and 
neck  391 

of  upper  ex- 


tremity 393 

Absorption,  cutaneous  395 

Black  glands  64 

Bile  141 

Bladder  of  female  213 

Blood  vessels  in  general  223 

Blood  401 

colouring  matter  of  404 

Cavities  of  nose  4 

Caecum  118 

Colon  119 

Corpus  pampiniforme  174 

Corpora  cavernosa  186 

Corpus  spongiosum  .188 

Canal  of  urethra  190 

Clitoris  201 

Canalis  arteriosus  220 

Cavae  299 

Coronary  veins  299 


Chorda  tympani  335 

Crassamentum  403 

Duodenum  1 1 1 

Ductus  communis  141 

Dartos  173 

Ductus  venosus  220 

Descending  cava  300 

External  hose  2 

Eustachion  tube  11 

Epididymis  177 

Fauces  28 

Foetus,  thorax  of  69 

heart  of  69 

lungs  of  69 

abdomen  of  217 

Female  organs  of  genera- 
tion 200 

Fallopian  tubes  209 

Gums  16 

Glandulae  molares  26 

Glottis  34 

Gastric  liquor  101 

Great  intestines  117 

Gall  bladder  and  duct  139 

Glandulae  renales  154 

Ganglions  321 

of  Gasser  327 

sphino  palatine  329 
cervical  361 

semilunar  367 

Glands,  structure  of  408 

Glossary  415 

Heart  50 

malformations  of  72 

nerves  of  363 

Hepatic  duct  139 

Hymen  202 

Hottentots,  peculiarity  of  216 

Intestines'  104 

villous  coat  of  105 
divison  of  109 


INDEX 


425 


Intestines,  small  110 

Integuments  of  penis  195 

Ilium  1 13 

Jejunum  113 

Kidneys  155 

Larynx  31 

arteries  and  nerves 
of  35 

Left  auricle  55 

ventricle  56 

Lungs  65 

Legallois  on  the  heart  79 

Liver  128 

ligaments  of  130 

Labia  externa  201 

Lacteals  389 

Mouth  14 

Mamma;  41 

Mediastinum  46 

Muscular  fibres  of  heart  57 

Mesentery  115 

Male  organs  of  generation  171 

Nose  1 

nerves  of  8 

Nerves  of  liver  136 

Neck  of  the  bladder  167 

Nerves,  structure  of  319 

accessory  347 

of  arm  348 

of  brain  323 

cervical  343 

circumflex  351 

crural  355 

cardiac  363 

of  diaphragm  246 

dorsal  352 

eighth  pair  336 

fourth  pair  325 

fifth  pair  326 

fibular  359 

glosso-pharyngeal  337 


internal  cutaneous  351 
Yol.  n. 


Nerves,  lumbar  353 


laryngeal  superior  339 
maxillary  inferior  332 
superior  329 


musculo  cutane 

ous 

348 

median 

348 

ninth  pair 

342 

olfactory  6. 

323 

optic 

324 

ophthalmic 

327 

obturator 

355 

parvagum 

338 

recurrent 

339 

radial 

350 

sixth  pair 

333 

seventh  pair 

334 

sacral 

356 

sciatic 

358 

sympathetic 

361 

splanchnic 

367 

third  pair 

325 

tibial  posterior 

360 

ulnar 

349 

(Esophagus 

94 

Omentum 

125 

Orifice  of  urethra 

167 

Ovaries 

210 

Parotid  gland 

25 

Pharynx 

37 

Pleurae 

45 

Pericardium 

49 

Pulmonary  arteries  and 

veins 

61 

Peritoneum 

90 

Pylorus 

102 

Pancreas 

141 

Prostate  gland 

113 

Penis 

184 

Prepuce 

196 

Placenta 

221 

Plexuses 

321 

pulmonary 

340 

brachial 

347 

54 


INDEX. 


426 


Plexuses  lumbar  354 

cardiac  366 

solar  367 

Rim  a glottidis  34 

Right  auricle  52 

ventricle  53 

Rectum  122 

Round  ligaments  209 

Schneiderian  membrane  5 
Sinuses  of  nose  12 

Soft  palate  17 

Salivary  glands  25 

Submaxillary  gland  26 

Sublingual  gland  26 

Saliva  26 

Sabatier  on  foetal  circula- 
tion 75 

Stomach  96 

lymphatics  and 
nerves  of  103 

Spleen  145 

Scrotum  171 

Serum  402 

Spermatic  cord  173 

Tongue  18 

papillae  of  20 

blood  vessels  of  23 
nerves  of  24 

Throat  28 

Tonsils  29 

Thyroid  gland  37 

Thorax  41 

Trachea  62 

Thymus  gland  69 

Tunica  vaginalis  175 

albuginea  176 

Testicle  177 

descent  of  218 

Thoracic  duct  387 

Uvula  17 

Urinary  organs  154 

Ureters  160 

Urinary  bladder  162 

Urethra  of  male  188 


Urethra  of  female  202 

Uterus  205 

changes  of,  in 
pregnancy  214  ' 

Umbilical  arteries  219 

Venae  cavae  61 

Valve  of  colon  120 

Vena  Portarum  134 

Vessels  of  liver  133 

Vas  deferens  180 

V efeiculas  seminales  181 

V agina  203 

Veins,  structure  of  233 

distribution  of  298 

Vena  azygos  301 

Veins,  axillary  308 

anomalies  ot  317 

basilic  308 

cephalic  308 

Cava  inferior  309 

capsular  312 

circumflex  314 

external  jugular  306 

emulgent  312 

external  iliac  314 

epigastric  315 

external  saphena  316 

femoral  315 

hepatic  311 

hypogastric  313 

intercostal  superior  303 
primitive  iliac  313 

jugular  internal  304 

lumbar  313 

middle  sacral  313 

mesenteric  superior31 1 
phrenic  inferior  310 

Vena  portarum  311 

Veins,  pulmonary  317 

subclavian  307 

splenic  311 

spermatic  312 

saphena  major  315 

vertebral  304 

vesical  313 


ANATOMICAL  PLATES, 


EXPLANATION  OF  THE  PLATES  OF  OSTEOLOGY. 


Plate  II. 

Fig.  1.  A Front-view  of  the  Male  Skeleton. 

A,  The  os  frontis.  B,  The  os  parietale.  C,  The  Coronal 
suture.  D,  The  squamous  part  of  the  temporal  bones.  E,  The 
squamous  suture.  F,  The  zygoma.  G,  The  mastoid  process. 

H,  The  temporal  process  of  the  sphenoid  bone.  I,  The  orbit. 
K,  The  os  malm.  L,  The  os  maxiilare  superius.  M,  Its  nasal 
process.  N,  The  ossa  nasi.  O,  The  os  unguis.  P,  The  maxilla 
inferior.  Q,  The  teeth,  which  are  sixteen  in  number  in  each 
jaw.  R,  The  seven  cervical  vertebrae,  with  their  intermediate 
cartilages.  S,  Their  Transverse  processes.  T,  The  twelve 
dorsal  vertebrae,  with  their  intermediate  cartilages.  U,  The 
five  lumbar  vertebrae.  V,  Their  transverse  process.  W,  The 
upper  part  of  the  os  sacrum.  X,  Its  lateral  parts.  The  holes 
seen  on  its  fore  part  are  the  passages  of  the  undermost  spinal 
nerves  and  small  vessels.  Opposite  to  the  holes,  the  marks  of 
the  original  divisions  of  the  bones  are  seen.  Y,  The  os  ilium. 
Z,  Its  crest  or  spine,  a,  The  anterior  spinous  processes,  b,  The 
brim  of  the  pelvis,  c,  The  ischiatic  notch,  d,  The  os  ischium, 
e,  Its  tuberosity,  f,  Its  spinous  process,  g,  Its  crus,  h,  The 
foramen  thyroideum.  i,  The  os  pubis,  k,  The  symphysis  pubis. 

I,  The  crus  pubis,  m,  The  acetabulum,  n,  The  seventh  or  last 
true  rib.  o,  The  twelfth  or  last  false  rib.  p,  The  upper  end  of 
the  sternum,  q,  The  middle  piece,  r,  The  under  end,  or  car- 
tilago  ensiformis.  s,  The  clavicle,  t,  The  internal  surface  of 
the  scapula,  u,  Its  acromion,  v,  Its  coracoid  process,  w.  Its 
cervix,  x,  The  glenoid  cavity,  y,  The  os  humeri,  z,  Its  head 
which  is  connected  to  the  glenoid  cavity.  1,  its  internal  tu- 
bercle. 2,  Its  interna!  tubercle.  3,  The  groove  for  lodging  the 
long  head  of  the  biceps  muscle  of  the  arm.  4,  The  internal 


428  Explanation  of  the  Plates  of  Osteology. 

condyle.  Between  4 and  5,  the  trochlea.  6,  The  radius.  7, 
Its  head.  8,  Its  tubercle.  9,  The  ulna.  10,  Its  coronoid 
process.  11,  12,  13,  14,  15,  16,  17,  18,  The  carpus ; compo- 
sed of  os  naviculare,  os  lunare,  os  cuneiform,  os  pisiforme, 
os  trapezium,  os  trapezoides,  os  magnum,  os  unciforme.  19, 
The  five  bones  of  the  metacarpus.  20,  The  two  bones  of  the 
thumb.  21,  The  three  bones  of  each  of  the  fingers.  22,  The 
os  femoris.  23,  Its  head.  24,  Its  cervix.  25,  The  trochan- 
ter major.  26,  trochanter  minor.  2 7,  The  internal  condyle. 
28,  The  external  condyle,  29,  The  rotula.  30,  The  tibia. 
31,  Its  head.  32,  Its  tubercle.  33,  Its  spine.  34,  The  mal- 
leolus interims.  35,  The  fibula.  36,  Its  head.  37,  The  mal- 
leolus externus.  The  tarsus  is  composed  of.  38,  The  astra- 
galus; 39,  fhe  os  calcis;  40,  The  os  naviculare;  41,  Three 
ossa,  cuneiformia,  and  the  os  cuboides,  which  is  not  seen  in 
this  figure.  42,  The  five  bones  of  the  metatarsus.  43,  The 
two  bones  of  the  great  toe.  44,  The  three  bones  of  each  of 
the  small  toes. 

Fig.  2.  A Front-view  of  the  Skull. 

A,  The  os  frontis.  B,  The  lateral  part  of  the  os  frontis, 
which  gives  origin  to  part  of  the  temporal  muscle.  C,  the  su- 
perciliary ridge.  D,  The  superciliary  hole  through  which  the 
frontal  vessels  and  nerves  pass.  EE,  The  orbitar  processes. 
F,  ( he  middle  of  the  transverse  suture.  G,  The  upper  part 
of  the  orbit.  H,  The  foramen  opticum.  I,  The  foramen  la- 
cerum.  K,  The  inferior  orbitar  fissure.  L,  The  os  unguis. 
M,  The  ossa  nasi.  N,  The  os  maxillare  superius.  O,  Its  na- 
sal process.  P,  The  external  orbitar  hole  through  which  the 
superior  maxillary  vessels  and  nerves  pass.  Q,  The  os  malse. 
It,  A passage  for  small  vessels  into  or  out  of,  the  orbit.  S, 
The  under  part  of  the  left  nostril.  T,  The  septum  narium. 
U,  The  os  spongiosum  superius.  V,  The  os  spongiosum  in- 
ferius.  W,  The  edge  of  the  alveoli,  or  spongy  sockets  for  the 
teeth.  X,  j he  maxilla  inferior.  Y,  The  passage  for  the  in- 
ferior maxillary  vessels  and  nerves. 

Fig.  3.  A Side-view  of  the  Skull. 

A,  The  os  frontis.  B,  ; he  coronal  suture.  C,  The  os  pa- 
rietale.  D,  An  arched  ridge  which  gives  origin  to  the  temporal 
muscle.  E,  The  squamous  suture.  F,  The  squamous  part  of 
the  temporal  bone:  and  lurther  forwards,  the  temporal  process 
of  the  sphenoid  bone.  G,  The  zygomatic  process  of  the  tempo- 
ral bone.  H,  i he  zygomatic  suture.  1,  The  mastoid  process  of 
the  temporal  bone.  K,  . he  meatus  auditorius  externus.  L,  The 
orbitar  piate  of  the  frontal  bone,  under  which  is  seen  the  trans- 


V.  I\  o , 


* AJ. • At-/  » A /tZ/i.  • Zl/,//tto 


Explanation  of  the  Plates  of  Osteology.  429 

verse  suture.  M,  The  pars  plana  of  the  ethmoid  bone.  N,  The 
os  unguis.  0,  The  right  os  nasi.  P,  The  superior  maxillary 
bone.  Q,  its  nasal  process.  II,  The  two  ilentes  incisores.  S, 
The  dens  caniuus.  T,  The  two  small  molares.  U,  The  three 
large  molares.  V,  The  os  malae.  W,  The  lower  jaw.  X,  Its 
angle.  Y,  The  coronoid  process.  Z,  The  condyloid  process 
by  which  the  jaw  is  articulated  with  the  temporal  bone. 

Fig.  4.  The  posterior  and  right  side  of  the  Skull. 

A,  The  os  frontis.  BB,  The  ossa  parietalia.  C,  The  sagit- 
tal suture.  D,  The  parietal  hole,  through  which  a small  vein 
runs  to  the  superior  longitudinal  sinus.  E,  The  lambdoid  su- 
ture. FF,  Ossa  triquetra.  G,  The  os  occipitis.  li,  The  squa- 
mous part  of  the  temporal  bone.  I,  The  mastoid  process.  K, 
The  zygoma.  L,  The  os  malm.  M,  The  temporal  part  of  the 
sphenoid  bone,  N,  The  superior  maxillary  bone  and  teeth. 

Fig.  5.  The  external  surface  of  the  Os  Frontis. 

A,  The  convex  part.  B,  Part  of  the  temporal  fossa.  C, 
The  external  auguiar  process.  D,  The  internal  angular  pro- 
cess. E,  The  nasal  process.  F,  The  superciliary  arch.  G, 
The  superciliary  hole.  H,  The  orbitar  plate. 

Fig.  6.  The  internal  surface  of  the  Os  Frontis. 

AA,  The  serrated  edge  which  assists  to  form  the  coronal 
suture.  B.  The  external  angular  process.  C,  The  internal 
angular  process.  D,  The  nasal  process.  E,  The  orbitar 
plate.  F,  The  cells  w liich  correspond  with  those  of  the  eth- 
moid bone.  G,  The  passage  from  the  frontal  sinus.  H,  The 
opening  which  receives  the  cribriform  plate  of  the  ethmoid 
bone.  I,  The  cavity  which  lodges  the  tore  part  of  the  brain. 
K,  The  spine  to  which  the  falx  is  fixed.  L,  The  groove  which 
lodges  the  superior  longitudinal  sinus. 

Plate  111. 

Fig,  1.  A Back-view  of  the  Skeleton. 

AA,  The  ossa  parietalia.  B,  The  sagittal  suture.  C,  The 
lambdoid  suture.  D,  The  occipital  bone.  E,  The  squamous 
suture.  F,  The  mastoid  process  of  the  temporal  bone.  G,  The 
os  malae.  H,  The  palate  piates  of  the  superior  maxillary  bones. 
I,  The  maxilla  inferior.  K,  The  teeth  of  both  jaws.  L , The 
seven  cervical  vertebrae.  M,  Their  spinous  processes.  N, 
Their  transverse  and  oblique  processes.  0,  The  last  of  the 
twelve  dorsal  vertebrae.  P,  Tiie  filth  or  last  lumbar  vertebra. 
Q.  The  transverse  processes.  R,  The  oblique  processes.  S,  The 
spinous  process.  T,  The  upper  part  of  the  os  sacrum.  U,  The 
posterior  holes  which  transmit  small  blood  vessels  and  nerves. 


430  Explanation  of  the  Plates  of  Osteology. 

V,  The  under  part  of  the  os  sacrum  which  is  covered  by  a 
membrane.  W,  The  os  coccygis.  X,  The  os  ilium.  Y,  Its 
spine  or  crest.  Z,  The  ischiatic  notch,  a.  The  os  ischium,  b, 
Its  tuberosity,  c,  Its  spine,  d,  The  os  pubis,  e,  The  foramen 
thyroideum.  f,  The  seventh  or  last  true  rib.  g,  The  twelfth  or 
last  false  rib.  h,  The  clavicle,  i,  The  scapula,  k,  Its  spine.  1, 
Its  acromion,  m,  Its  cervix,  n,  Its  superior  costa,  o,  Its  pos- 
terior costa.  p,  Its  inferior  costa.  q,  The  os  humeri,  r,  The  ra- 
dius. s,  The  ulna,  t,  Its  olecranon,  u,  All  the  bones  of  the 
carpus,  excepting  the  os  pisiforme,  which  is  seen  in  plate  II. 
fig.  1.  v,  The  five  bones  of  the  metacarpus,  w,  The  two  bones 
ot  the  thumb,  x,  The  three  bones  of  each  of  the  fingers,  y.  The 
two  sesamoid  bones  at  the  root  of  the  left  thumb,  z,  The  os 
femoris.  1,  The  trochanter  major.  2,  The  trochanter  minor. 
3,  The  linea  aspera.  4,  The  internal  condyle.  5,  The  exter- 
nal condyle.  6 6,  The  semilunar  cartilages.  7,  The  tibia.  8, 
The  malleolus  internus.  9,  The  fibul.  10,  The  malleolus  ex- 
ternus.  1 1,  The  tarsus.  12,  The  metatarsus.  13,  The  toes. 

Fig.  2.  The  external  Surface  of  the  Left  Os  Parietale. 

A,  The  convex  smooth  surface.  B,  The  parietal  hole.  C, 
An  arch  made  by  the  beginning  of  the  temporal  muscle. 

Fig.  3.  The  Internal  Surface  of  the  same  bone. 

A,  Its  superior  edge,  which,  joined  with  the  other,  forms 
the  sagittal  suture.  B,  The  anterior  edge  which  assists  in  the 
formation  of  the  coronal  suture.  C,  The  inferior  edge  for 
the  squamous  suture.  D,  The  posterior  edge  for  the  lamb- 
doid  suture.  E,  A depression  made  by  the  lateral  sinus.  F, 
The  prints  of  the  arteries  of  the  dura  mater. 

Fig.  4.  The  external  Surface  of  the  Left  Os  Temporis. 

A,  The  squamous  part.  B,  The  mastoid  process.  C,  The 
zygomatic  process.  D,  The  styloid  process.  E,  The  petro- 
sal process.  F,  The  meatus  auditorius  externus.  G,  The 
glenoid  cavity  for  the  articulation  of  the  lower  jaw.  H,  The 
foramen  stylo-mastoideum  for  the  portio  dura  of  the  seventh 
pair  of  nerves.  1,  Passages  for  blood  vessels  into  the  bone. 
K,  The  foramen  mastoideum  through  which  a vein  goes  to 
the  lateral  sinus. 

Fig.  5.  The  Internal  Surface  of  the  Left  Os  Temporis. 

A,  The  squamous  part;  the  upper  edge  of  which  assists  in 
forming  the  squamous  suture.  B,  The  mastoid  process.  C, 
The  styloid  process.  D,  The  pars  petrosa.  E,  The  entry  of 
the  seventh  pair,  or  auditory  nerve.  F,  The  fossa,  which  lodges 
a part  of  the  lateral  sinus.  G,  The  foramen  mastoideum. 


Explanation  of  the  Plates  of  Osteology*  431 

Fig.  6.  The  External  Surface  of  the  Osseous  Circle,  which 
terminates  the  meatus  auditorious  externus. 

A,  The  anterior  part.  B,  A small  part  of  the  groove  in 
which  the  membrana  tympani  is  fixed. 

N.  B.  This,  with  the  subsequent  bones  of  the  ear,  are  here 
delineated  as  large  as  the  life. 

Fig.  7.  The  Internal  Surface  of  the  Osseous  Circle. 

A,  The  anterior  part.  B,  The  groove  in  which  the  mem- 
brana tympani  is  fixed. 

Fig.  8.  The  Situation  and  Connexion  of  the  Small  Bones  of 
the  Ear. 

A,  The  malleus.  B,  The  incus.  C,  The  os  orbiculare. 

D,  The  stapes. 

Fig.  9.  The  Malleus,  with  its  Head,  Handle,  and  Small 
Processes. 

Fig.  10.  The  Incus,  with  its  Body,  Superior  and  Inferior 
Branches. 

Fig.  11.  The  Os  Orbiculare. 

Fig.  12.  The  Stapes,  with  its  Head,  Base,  and  two  Crura. 
Fig.  13.  An  Internal  View  of  the  Labyrinth  of  the  Ear. 
A,  The  hollow  part  of  the  cochlea,  which  forms  a share  of 
the  meatus  auditorious  internus.  B,  The  vestibulum.  CCC, 
The  semicircular  canals. 

Fig.  14.  An  External  View  of  the  Labyrinth. 

A,  The  semicircular  canals.  B,  The  fenestra  ovalis  which 
leads  into  the  vestibulum.  C,  The  fenestra  rotunda  which 
opens  into  the  cochlea.  D,  The  different  turns  of  the  cochlea. 
Fig.  15.  The  Internal  Surface  of  the  Os  Sphenoides. 
AA,  The  temporal  processes.  BB,  The  pterygoid  proces- 
ses. CC,  The  spinous  processes.  DD,  The  anterior  clinoid 
processes.  E,  The  posterior  clinoid  process.  F,  The  ante- 
rior process  which  joins  the  ethmoid  bone.  G,  The  sella  tur- 
cica for  lodging  the  glandula  pituitaria.  H,  The  foramen  op- 
ticum.  K,  The  foramen  lacerum.  L,  The  foramen  rotun- 
dum.  M,  The  foramen  ovale.  N,  The  foramen  spinale. 
Fig.  16.  The  External  Surface  of  the  Os  Sphenoides. 
AA,  The  temporal  processes.  BB,  The  pterygoid  proces- 
ses. CC,  The  spinous  processes.  D,  The  processus  azygos. 

E,  The  small  triangular  processes  which  grow  from  the  body 
of  the  bone.  FF,  The  orifices  of  the  sphenoid  sinuses.  G, 
The  foramen  lacerum.  H,  The  foramen  rotundum.  I,  The 
foramen  ovale.  K,  The  foramen  pterygoideum. 


432  Explanation  of  the  Plates  of  Osteology. 

Fig.  17.  The  External  View  of  the  Os  Etiimoides. 

A,  The  nasal  lamella.  BB,  The  grooves  between  the  nasal 
lamella  and  ossa  spongiosa  superiora.  CC,  The  ossa  spongi- 
osa  superiora.  DD,  The  sphenoidal  cornua.  See  Fig.  16.  E. 

Fig.  18.  The  Internal  view  of  the  Os  Ethmoides. 

A,  The  crista  galli.  B,  The  cribriform  plate,  with  the  dif- 
ferent passages  of  the  olfactory  nerves.  CC,  Some  of  the 
ethmoidal  cells.  D,  The  right  os  planum.  EE,  The  Sphe- 
noidal cornua. 

Fig.  19.  The  right  SA^noidal  Cornu. 

Fig.  20.  The  left  Sphenoidal  Cornu. 

Fig.  21.  The  External  Surface  of  the  Os  Occipitis. 

A,  The  upper  part  of  the  bone.  B,  The  superior  arched 
ridge.  C,  The  inferior  arched  ridge.  Under  the  arches  are 
prints  made  by  the  muscles  of  the  neck.  DD,  The  two  con- 
dyloid processes  which  articulate  the  head  with  the  spine.  E, 
The  cuneiform  process.  F,  The  foramen  magnum  through 
which  the  spinal  marrow  passes.  GG,  The  posterior  condy- 
loid foramina  which  transmit  veins  into  the  lateral  sinuses. 
HII,  The  foramina  lingualia  for  the  passage  of  the  ninth  pair 
of  nerves. 

Fig.  22.  The  Internal  Surface  of  the  Os  Occipitis. 

AA,  The  two  sides  which  assist  to  form  the  lambdoid  suture. 
B,  The  point  of  the  cuneiform  process,  where  it  joins  the 
sphenoid  bone.  CC,  The  prints  made  by  the  posterior  lobes  of 
the  brain.  DD,  Prints  made  by  the  lobes  of  the  cerebellum. 
E,  The  cruciform  ridge  for  the  attachment  of  the  process  of  the 
dura  mater.  F,  The  course  of  the  superior  longitudinal  si- 
nuses. GG,  The  course  of  the  two  lateral  sinuses.  H,  The 
foramen  magnum.  II,  The  posterior  condyloid  foramina. 

Plate  IV. 

Fig.  1.  A Side-view  of  the  Skeleton. 

A A,  The  ossa  parietalia.  B,  The  sagittal  suture.  C,  The  os 
occipitis.  DD,  The  lambdoid  suture.  E,  The  squamous  part 
of  the  temporal  bone.  F,  The  mastoid  process.  G,  The  meatus 
auditorius  externus.  H,  The  os  frontis.  I,  The  os  malae.  K, 
The  os  maxillare  superius.  L,  The  maxilla  inferior.  M,  The 
teeth  of  both  jaws.  N,  The  seventh,  or  last  cervical  vertebra. 
0,  The  spinous  processes.  P,  Their  transverse  and  oblique 
processes.  Q,  The  twelfth  or  last  dorsal  vertebra.  R,  The 
fifth,  or  last  lumbar  vertebra.  S,  The  spinous  processes.  T, 
Openings  between  the  vertebrae  for  the  passage  of  the  spinal 
nerves.  U,  The  under  end  of  the  os  sacrum.  V,  The  oscoc- 


ffl  o 


Explanation  of  the  Elates  of  Osieotogf,  433 

eygi;.  W,  The  os  ilium.  X,  The  anterior  spinous  processes, 
Y,  The  posterior  spinous  processes.  Z,  Ischiatic  notch,  a,  The 
right  os  ilium,  b,  The  ossa  pubis,  c,  The  tuberosity  of  the 
left  os  ischium,  d,  The  Scapula,  e,  Its  spine,  f,  The  os  hu- 
meri. g,  The  radius.  h, The  ulna.  i,  The  carpus,  k,  The  me- 
tacarpal bone  of  the  thumb.  1,  The  metacarpal  bones  of  the 
fingers,  m,  The  two  bones  of  the  thumb,  n,  The  three  bones 
of  each  of  the  fingers,  o,  The  os  femoris.  p,  Its  head,  q,  The 
trochanter  major,  r,  The  external  condyle,  s,  The  rotula.  t. 
The  tibia,  u,  The  fibula,  v,  The  malleolus  externus.  w.  The 
astragalus,  x,-  The  os  calcis.  y,  The-os  naviculare.  z,  The 
three  ossa  cuneiforma.  l,The  os  cuboides.  2,  The  five  m - 
tatarsal  bones.  3,  The  two  bones  of  the  great  toe.  4,  The 
three  bones  of  each  of  the  small  toes. 

Fig.  2.  A view  of  the  Internal  Surface  of  the  Base  of  the 

Skull. 

AAA,  The  two  tables  of  the  skull  with  the  diploe.  BE, 
The  orbitar  plates  of  the  frontal  bone.  C,  The  crista  gal  .. 
with  cribriform  plate  of  the  ethmoidal  bones  on  each  side  ol 
it,  through  which  the  first  pair  of  nerves  pass.  D,  The  cunei- 
form process  of  the  occipital  bone.  E,  The  cruciform  ridge. 
F,  The  foramen  magnum  for  the  passage  of  the  spinal  mar- 
row. G,  The  zygoma,  made  by  the  joining  of  the  zygomatic 
processes  of  the  os  temporum  and  os  malse.  H,  The  pars  squa- 
mosa of  the  os  temporis.  I,  The  pars  mammillaris.  K,  The 
pars  petrosa.  L,  The  temporal  process  of  the  sphenoid  bone. 
MM,  The  anterior  clinoid  processes.  N,  The  posterior  cli- 
noid  process.  O,  The  sella  turcica.  P,  The  foramen  opticum 
for  the  passage  of  the  optic  nerve  and  ocular  artery  of  the 
leftside.  Q,  The  foramen  lacerum,  for  the  third,  fourth 
sixth,  and  first  of  the  fifth  pair  of  nerves  and  ocular  vein.  B, 
The  foramen  rotundum,  for  the  second  of  the  fifth  pair.  S, 
The  foramen  ovale,  for  the  third  of  the  fifth  pair.  T,  The 
foramen  spinaie,  for  the  principal  artery  of  the  dura  mater. 
U,  The  entry  of  the  auditory  nerve.  V,  The  passage  for  the 
lateral  sinus.  W,  The  passage  of  the  eighth  pair  of  nerves. 
X,  The  passage  of  the  ninth  pair. 

Fig.  3.  A View  of  the  External  Surface  of  the  Base  of  the 
Skull. 

A,  The  two  dentes  incisores  of  the  right  side.  B,  The  dens 
caninus.  C,  The  two  small  molares.  D,  The  three  large  mo 
lares.  E,  The  foramen  incisivum,  which  gives  passage  to  smalt 
blood  vessels  and  nerves.  F,  The  palate  plates  of  the  ossa 
maxillaria  and  palati,  joined  by  the  longitudinal  and  trails- 
•’  erse  palate  sutures.  G,  The  foramen  palatinum  posterius,  fe: 

Vol.ii,  55 


434  Explanation  of  the  Plates  of  Osteology . 

. he  palatine  vessels  and  nerves.  H,  The  os  maxillare  superior* 
of  the  right  side.  I,  The  os  malm.  K,  The  zygomatic  process 
of  the  temporal  bone.  L,  The  posterior  extremity  of  the  ossa 
spongiosa.  M,  The  posterior  extremity  of  the  vomer  which, 
forms  the  back  part  of  the  septum  nasi.  N,  The  pterygoid  pro- 
cess of  the  right  side  of  the  sphenoid  bone.  00,  The  foramina 
ovalia.  PP,  The  foramina  spinalia.  QQ,  The  passages  of  the 
internal  carotid  arteries.  R,  A hole  between  the  point  of  each 
pars  petrosa  and  cuneiform  process,  of  the  occipital  bone,  which 
is  filled  up  with  a ligamentous  substance  in  the  recent  subject. 
S3,  The  passage  of  the  left  lateral  sinus.  T,  The  posterior  con- 
dyloid foramen  of  the  left  side.  U,  The  foramen  mastoideum. 
V,  The  foramen  magnum.  W,  The  inferior  orbitar  fissure.  X, 
The  glenoid  cavity,  for  the  articulation  of  the  lower  jaw.  Y, 
The  squamous  part  of  the  temporal  bone.  Z,  The  mastoid 
process,  at  the  inner  side  of  which  is  a fossa  for  the  posterior 
belly  of  the  digastric  muscle,  a,  The  styloid  process,  b,  The 
meatus  auditorius  externus.  c,  The  left  condyle  of  the  occi- 
pital bone,  d,  The  perpendicular  occipital  spine,  ee,  The 
inferior  horizontal  ridge  of  the  occipital  bone,  ff,  The  supe- 
rior horizontal  ridge,  which  is  oppposite  to  the  crucial  ridge 
where  the  longitudinal  sinus  divides  to  form  the  lateral  sinu- 
ses. ggg,  The  lambdoid  suture,  h,  The  left  squamous  su- 
ture. i,  The  parietal  bone. 

Fig.  4.  The  anterior  surface  of  the  Ossa  Nasi. 

A,  The  upper  part  which  joins  the  os  frontis.  B,  The  un- 
der end,  which  joins  the  cartilage  of  the  nose.  C,  The  in- 
ner edge,  where  they  join  each  other. 

Fig.  5.  The  posterior  surface  of  the  Ossa  Nasi. 

AA,  Their  cavity,  which  forms  part  of  the  arch  of  the  nose. 
BB,  Their  ridge  or  spine,  which  projects  a little  to  be  fixed 
to  the  fore  part  of  the  septum  narium. 

Fig.  6.  The  external  surface  of  the  Os  Maxillare  Superius 
of  the  left  side. 

A,  The  nasal  process.  B,  The  orbitar  plate.  C,  The  un- 
equal surface  which  joins  the  os  malse.  D,  The  external  orbitar 
hole.  E,  The  opening  into  the  nostril.  F,  The  palate-plate. 
G,  The  maxillary  tuberosity.  H,  Part  of  the  os  palati.  I, 
The  two  dentes  incisores.  K,  The  dens  caninus.  L,  The  two 
small  dentes  niolares.  M,  The  three  large  dentes  molares. 
Fig.  7.  The  internal  surface  of  the  Os  Maxillare  Superius 
and  Os  Palati. 

A,  The  nasal  process.  BB,  Eminences  for  the  connexion 
of  the  os  spongiosum  inferius.  D,  The  under  end  of  the  la- 
chrymal groove.  E,  The  antrum  maxillare.  F,  The  nasal  spine. 


Explanation  of  the  Plates  of  Osteology . 435 

"between  which  and  B is  the  cavity  of  the  nostril.  G,  The 
palate-plate.  H,  The  orbitar  part  of  the  os  palati.  I,  The 
nasal  plate.  K,  The  suture  which  unites  the  maxillary  and 
palate  bones.  The  pterygoid  process  of  the  palate  bone. 

Fig.  8.  The  external  surface  of  the  right  Os  Unguis. 

A,  The  orbitar  part.  B,  The  lachrymal  part.  C,  The 
ridge  between  them. 

Fig.  9.  The  internal  surface  of  the  right  Os  Unguis. 

This  side  of  the  bone  has  a furrow  opposite  to  the  external 
ridge;  all  behind  this  is  irregular,  where  it  covers  part  of  the 
ethmoidal  cells. 

Fig.  10.  The  external  surface  of  the  left  Os  Mala:. 

A,  The  superior  orbitar  process.  B,  The  inferior  orbitar 
process.  C,  The  malar  process.  D,  The  zygomatic  process. 
E,  The  orbitar  plate.  F,  A passage  for  small  vessels  into  or 
out  of  the  orbit. 

Fig.  11.  The  internal  surface  of  the  left  Os  Mala:. 

A,  The  superior  orbitar  process.  B,  The  inferior  orbitar 
process.  C,  The  malar  process.  D,  The  zygomatic  process. 
E,  The  interna)  orbitar  plate  or  process. 

Fig.  12.  The  externa!  surface  of  the  right  Os  Spongiosum 
Inferius. 

A,  The  anterior  part.  B,  The  hook-like  process  for  cover- 
ing part  of  the  antrum  maxillare.  C,  A small  process  which 
covers  part  of  the  under  end  of  the  lachrymal  groove.  D, 
The  inferior  edge  turned  a little  outwards. 

Fig.  13.  The  internal  surface  of  the  Os  Spongiosum  Inferius. 

A,  The  anterior  extremity.  B,  The  upper  edge  which  joins 
the  superior  maxillary  and  palate  bones. 

Fig.  14.  The  posterior  and  external  surface  of  the  right  Os 
Palati. 

A,  The  orbitar  process.  B,  The  nasal  lamella.  C,  The 
pterygoid  process.  D,  The  palate  process. 

Fig.  15.  The  interior  and  external  surface  of  the  right  Os 
Palati. 

A,  The  orbitar  process.  B,  An  opening  through  which  the 
lateral  nasal  vessels  and  nerves  pass.  C,  The  nasal  lamella. 
D,  The  pterygoid  process.  E,  The  posterior  edge  of  the  pa- 
late process  for  the  connexion  of  the  velum  palati.  F,  The 
inner  edge  by  which  the  two  ossa  palati  are  connected. 

Fig.  16.  The  right  side  of  the  Vomer. 

A,  The  upper  edge  which  joins  the  nasal  lamella  of  th 


1 36  Explanation  of  the  Plates  of  Osteology. 

ethmoid  bone  and  the  middle  cartilage  of  the  nose.  B,  The 
inferior  edge,  which  is  connected  to  the  superior  maxillary 
anti  palate  bones.  C,  The  superior  and  posterior  part  which 
receives  the  processes  azygos  of  the  sphenoid  bone. 

Fig,  17.  The  Maxilla  Inferior. 

A,  The  chin.  B,  The  base  and  left  side.  C,  The  angle. 
1),  The  coronoid  process.  E,  The  condyloid  process.  F,  The 
beginning  of  the  inferior  maxillary  canal  of  the  right  side, 
for  the  entry  of  the  nerves  and  blood  vessels.  G,  The  ter- 
n .'.nation  of  the  left  canal.  H,  The  two  dentes  incisores.  I, 
The  dens  caninus.  K,  The  two  small  molares.  L,  The  three 
large  molares. 

Fig.  18.  The  different  classes  of  the  Teeth. 

1 , 2,  A fore  and  back  view  of  the  two  anterior  dentes  in- 
cisores of  the  lower  jaw.  3,  4,  Similar  teeth  of  the  upper 
jaw.  5,  6,  A fore  and  back  view  of  the  dentes  canini.  7,  8, 
The  anterior  dentes  molar, es.  9,  10,  11,  The  posterior  den- 
tes molares.  12,  13,  14,  15,  16,  Unusual  appearances  in  the 
shape  and  size  of  the  teeth. 

Fig.  19.  The  external  surface  of  the  Os  Hyoides. 

A,  The  body.  BB,  The  cornua.  CC,  The  appendices. 
Plate  V. 

Fig.  1.  A Posterior  View*  of  the  Sternum  and  Clavicles, 
with  the  ligament  connecting  the  clavicles  to  each  other, 
a.  The  posterior  surface  of  the  sternum,  bb,  The  broken 
end  of  the  clavicle,  cccc,  The  tubercles  near  the  extremity 
of  each  clavicle,  d,  The  ligament  connecting  the  clavicles. 
Fig.  2.  A Fore-view  of  the  Left  Scapula,  and  a half  of  the 
Clavicle,  with  their  Ligaments, 
a,  The  spine  of  the  scapula,  b,  The  acromion,  c,  The  infe- 
rior angle,  d,  Inferior  costa,  e,  Cervix,  f,  Glenoid  cavity 
covered  with  cartilage  for  the  arm-bone,  gg,  The  capsular  liga- 
ment of  the  joint,  h,  Coracoid  process,  i,  The  broken  end  of 
the  clavicle,  k,  Its  extremity  joined  to  the  acrimon.  1,  A 
ligament  coming  out  single  from  the  acromion  to  the  coracoid 
process,  m,  A ligament  coming  out  single  from  the  acromion, 
and  dividing  into  two,  which  are  fixed  to  the  coracoid  process. 
Fig.  3.  The  Joint  of  the  elbow  of  the  left  arm,  with  the  Li- 
gaments. 

a,  The  os  humeri,  b,  Its  internal  condyle,  cc,  The  two 
prominent  parts  of  its  trochlea  appearing  through  the  capsu- 
lar ligament,  d,  The  ulna,  e,  The  radius,  f,  The  part  of 
the  ligament  including  the  head  of  the  radius. 


Ava  l < > my  y Pla t 


Explanation  of  the  Plates  of  Osteology.  43? 

Fig.  4.  The  Bones  of  the  Right  Hand,  with  the  Palm  in  view. 

a The  radius,  b,  The  ulna,  c,  The  scaphoid  bone  of  the 
carpus,  d,  The  os  lunare-  e,  The  os  cuneiforme.  f,  The  os 
pisiforme.  g,  Trapezium,  h,  Trapezoides.  i,  Magnum,  k, 
Unciforme.  1,  The  four  metacarpal  bones  of  the  fingers,  m, 
The  first  phalanx,  n,  The  second  phalanx,  o,  The  third 
phalanx,  p,  The  metacarpal  bone  of  the  thumb,  q,  The  first 
joint,  r,  The  second  joint. 

Fig.  5.  The  posterior  View  of  the  bones  of  the  Left  Hand. 

The  explication  of  Fig.  4.  serves  for  this  figure;  the  same 
letters  pointing  out  the  same  bones,  though  in  a different  view. 
Fig.  6.  The  Upper  Extremity  of  the  Tibia,  with  the  Semilunar 
Cartilages  of  the  Joint  of  the  Knee,  an*l  some  Ligaments. 

a,  The  strong  ligament  which  connects  the  rotulato  the  tu- 
bercle of  the  tibia,  bb,  The  parts  of  the  extremity  of  the  ti- 
bia, covered  with  cartilage,  which  appear  within  the  semilu- 
nar cartilages,  cc,  The  semilunar  cartilages,  d,  The  two 
parts  of  what  is  called  the  cross  ligament. 

Fig.  7.  The  Posterior  view  of  the  Joint  of  the  Right  Knee. 

a,  The  os  femoris  cut.  b,  Its  internal  condyle,  c,  Its  ex- 
ternal condyle,  d,  The  back  part  of  the  tibia,  e,  The  superior 
extremity  of  the  fibula,  f,  The  edge  of  the  internal  semilunar 
cartilage,  g,  An  oblique  ligament,  h,  A large  perpendicular 
ligament,  i,  A ligament  connecting  the  femur  and  fibula. 
Fig.  8.  The  Anterior  view  of  the  Joint  of  the  Right  Knee. 

b,  The  internal  condyle,  c,  Its  external  condyle,  d,  The 
part  of  the  os  femoris,  os  which  the  patella  moves,  e,  A per- 
pendicular ligament.  * fit1,  The  two  parts  of  the  crucial  liga- 
ments. gg,  The  edges  of  the  two  moveable  semilunar  carti- 
lages. h,  The  tibia,  i,  The  strong  ligament  of  the  patella. 

k,  The  back  part  of  it  where  the  fat  has  been  dissected  away, 

l,  The  external  depression,  m,  The  internal  one.  n,  The 
cut  tibia. 

Fie.  9.  A View  of  the  inferior  part  of  the  Bones  of  the 
Right  Foot. 

a,  The  great  knob  of  the  os  calcis.  b,  A prominence  on  its 
outside,  c,  The  hollow  for  the  tendons,  nerves  and  blood  ves  - 
sels. d,  The  anterior  extremity  of  the  os  calcis.  e,  Part  of  the 
astragalus,  f,  Its  head  covered  with  cartilage,  g,  The  internal 
prominence  of  the  os  naviculare.  h,  The  os  cuboides.  i,  The 
os  cuneiform  internum ; k, — Medium  : 1, — Externum,  m, 
The  metatarsal  bones  of  the  four  lesser  toes,  n,  The  first — o, 
The  second — p,  The  third  phalanx  of  the  four  lesser  toes,  q, 


438  Explanation  of  the  Plates,  of  Osteology . 

The  metatarsal  bones  of  the  great  toe.  r,  Its  first — s,  Its  se- 
cond joint. 

Fig.  10.  The  Inferior  Surface  of  the  two  large  Sesamoid 
Bones,  at  the  first  Joint  of  the  Great  Toe. 

Fig.  11.  The  Superior  View  of  the  Bones  of  the  Right  Foot, 
a,  b,  as  in  Fig.  9.  c,  The  superior  head  of  the  astragalus. 

d,  &c.  as  in  Fig.  9. 

Fig.  12.  The  view  of  the  Sole  of  the  Foot,  with  its  ligaments. 

a,  The  great  knob  of  the  os  calcis.  b,  The  hollow  for  the 
tendons,  nerves,  and  blood  vessels,  c,  The  sheaths  of  the 
flexores  pollicis  and  digitorum  long!  opened,  d,  The  strong 
cartilaginous. ligament  supporting  the  head  of  the  astragalus. 

e,  h,  Two  ligaments  which  unite  into  one,  and  are  fixed  to 
the  metatarsal  bone  of  the  great  toe.  f,  A ligament  from 
the  knob  of  the  os  calcis  to  the  metatarsal  bone  of  the  little 
toe.  g,  A strong  triangular  ligament,  which  supports  the 
bones  of  the  tarsus,  i,  The  ligaments  of  the  joints  of  the 
five  metatarsal  bones. 

Fig.  13.  a,  The  head  of  the  thigh  bone  of  a child,  b,  The 
lmamentum  rotundum  connecting  it  to  the  acetabulum,  c, 
The  capsular  ligament  of  the  joint  with  its  arteries  injected, 
d,  The  numerous  vessels  of  the  mucilaginous  gland  injected. 
Fig.  14.  The  Back-view  of  the  Cartilages  of  the  Larynx, 
with  the  Os  Hyoides. 

a,  The  posterior  part  of  the  base  of  the  os  hyoides.  bb,  Its 
cornua,  c,  The.  appendix  of  the  right  side,  d,  A ligament  sent 
out  from  the  appendix  of  the  left  side,  to  the  styloid  process 
of  the  temporal  bone,  e,  The  union  of*the  base  with  the  left 
cornu,  ff,  The  posterior  sides  of  (g)  the  thyroid  cartilage, 
hh,  Its  superior  cornua,  ii,  Its  inferior  cornua,  k,  The  cri- 
coid cartilage.  11,  The  arytenoid  cartilages,  m,  The  entry  into 
the  lungs,  named  glottis,  n,  The  epiglottis,  oo,  The  superior 
cartilages  of  the  trachea,  p,  Its  ligamentous  back  part. 

Fig.  15.  The  superior  Concave  surface  of  the  Sesamoid  Bones 
at  the  first  joint  of  the  Great  Toe,  with  their  Ligaments, 
a,  Three  sesamoid  bones,  b,  The  ligamentous  substance  in 
which  they  are  formed. 


/ 


Explanation  of  the  Plates  of  the  Muscles.  439 


EXPLANATION  OF  PLATES  VI.  and  VII. 

PLATE  VI. 

Fig.  I.  The  Muscles  immediately  under  the  common  te- 
guments on  the  anterior  part  of  the  body  are  represented  on 
the  right  side;  and  on  the  left  side  the  Muscles  are  seen 
which  come  in  view  when  the  exterior  ones  are  taken  away. 

A,  The  frontal  muscle.  B,  The  tendinous  aponeurosis  which 
joins  it  to  the  occipital;  hence  both  named  occipitofrontalis . 
C,  Attollens  aurem.  D,  The  ear.  E,  Anterior  auris.  FF,  Or- 
bicularis palpebrarum.  G,  Levator  labii  superioris  alaeque 
nasi.  H,  Levator  anguli  oris.  I,  Zygomaticus  minor.  K,  Zy- 
gomaticus  major.  L5  Masseter.  M,  Orbicularis  oris.  N,  De- 
pressor labii  inferioris.  O,  Depressor  anguli  oris.  P,  Bucci- 
nator. QQ,  Platysma  myoides.  RR,  Sterno-cleido-mastol- 
deus.  S,  Part  of  the  trapezius.  T,  Part  of  the  scaleni. 

Superior  Extremity. — U,  Deltoides.  V,  Pectoralis  ma- 
jor. W,  Part  of  the  latissimus  dorsi.  XX,  Biceps  flexor  cu- 
biti.  YY,  Part  of  the  triceps  extensor.  ZZ,  The  beginning  of 
the  tendinous  aponeurosis,  (from  the  biceps,)  which  is  spread 
over  the  muscles  of  the  fore-arm.  aa,  Its  strong  tendon  insert- 
ed into  the  tubercle  of  the  radius,  bb,  Part  of  the  brachialis  in- 
ternus.  c,  Pronator  radii  teres,  d,  Flexor  carpi  radialis.  e, 
Part  of  the  flexor  carpi  ulnaris.  f,  Palmaris  longus.  g,  Apo- 
neurosis palmaris.  3,  Palmaris  brevis.  1,  Ligamentum  carpi 
annulare.  2 2,  Abductor  minimi  digiti.  h,  Supinator  radii  lon- 
gus. i,  The  tendons  of  the  thumb,  k,  Abductor -pollicis.  1, 
Flexor  pollicis  longus.  mm,  The  tendons  of  the  flexor  sublimis 
perforatus,  profundus  perforans,|andlumbricales.  The  sheaths 
are  entire  in  the  right  hand, — in  the  left  cut  open  to  show  the 
tendons  of  the  flexor  profundus  perforating  the  sublimis. 

Muscles  not  referred  to — in  the  left  superior  extremity. — 
n,  Pectoralis  minor,  seu  serratus  anticus  minor,  o,  The  two 
heads  of  (xx)  the  biceps,  p,  Coraco-brachialis.  qq,  The  long 
head  of  the  triceps  extensor  cubiti.  rr,  Teres  major,  ss,  Sub- 
scapularis.  tt,  Extensores  radiales.  u,  Supinator  brevis,  v, 
The  cut  extremity  of  the  pronator  teres,  w,  Flexor  sublimis 
perforatus.  x,  Part  of  the  flexor  profundus,  y.  Flexor  pol- 
licis longus.  z,  Part  of  the  flexor  pollicis  brevis.  4,  Abduc- 
tor minimi  digiti.  5,  The  four  lumbricales. 

Trunk.— 6,  Serrated  extremities  of  the  serratus  anticus  ma- 


440  Explanation  of  the  Plates  of  the  Muscles , 

jor.  7 7,  Obliquus  externus  abdominis.  8 8,  The  linea  alba. 
9,  The  umbilicus.  10,  Pyramidalis.  11  11,  The  spermatic 
cord.  On  the  left  side  it  is  covered  by  the  cremaster-  12 12, 
Rectus  abdominis.  13,  Obliquus  internus.  14  14,  &c.  In- 
tercostal muscles. 

Inferior  Extremities. — a a , The  gracilis,  b b.  Parts  of 
the  triceps,  c c,  Pectinalis.  d d,  Psoas  magus,  e e,  Iliacus  in- 
ternus. /,  Part  of  the  glutasus  medius.  g,  Part  of  the  glutseus 
minimus.  li,  Cut  extremity  of  the  rectus  femoris.  ii,  Vastus 
externus.  k,  Tendon  of  the  rectus  femoris.  1 1,  Vastus  inter- 
nus. # Sartorius  muscle.  **.  Fleshy  origin  of  the  tensor  vaginas 
femoris  or  membranosus.  Its  tendinous  aponeurosis  covers 
(«)  the  vastus  externus  on  the  right  side,  m in,  Patella,  nn, 
Ligament  or  tendon  from  it  to  the  tibia,  o,  Rectus  femoris. 
p,  Crurasus.  q q,  The  tibia,  r r,  Part  of  the  Gemellus,  or  gas- 
trocnemius externus.  sss , Part  of  the  soleus  or  gastrocnemius 
internus.  t,  Tibialis  auticus.  u , Tibialis  posticus,  v v , Pero- 
naei  muscles,  tv  w,  Extensor  longus  digitorurn  pedis,  a;  a;,  Ex- 
tensor longus  pollicis  pedis,  y,  Abductor  pollicis  pedis. 

Fig.  2.  The  Muscles,  Glands,  &c.  of  the  Left  Side  of  the 
face  and  neck,  after  the  common  Teguments  and  Platys- 
ma  myoides  have  been  taken  off. 

a,  The  frontal  muscle,  b,  Temporalis  and  temporal  arte- 
ry. c,  Orbicularis  palpebrarum,  d,  Levator  labii  superioris 
alaeque  nasi,  e,  Lavator  anguli  oris,  f,  Zygomaticus.  g, 
Depressor  labii  inferioris.  h,  Depressor  anguli  oris,  i,  Buc- 
cinator. k,  Masseter.  1 1,  Parotid  gland,  m,  Its  duct,  n, 
Sterno-cleido-mastoideus.  o,  Part  of  the  trapezius,  p,  Ster- 
no-hyoideus.  q,  Sterno-thyroideus.  r,  Omo-hyoideus.  f,  Le- 
vator scapulae,  tt,  Scaleni.  u,  Part  of  the  splenius. 

Fig.  3.  The  Muscles  of  the  Face  and  Neck  in  view  after 
the  exterior  ones  are  taken  away, 
aa,  Corrugator  supercilii.  b,  Temporalis,  c,  Tendon  of 
the  levator  palpebrae  superioris.  - d,  Tendon  of  the  orbicula- 
ris palpebrarum,  e,  Masseter.  f,  Buccinator,  g,  Levator 
anguli  oris,  h,  Depressor  labii  superioris  alseque  nasi,  i,  Or- 
bicularis oris,  k,  Depressor  anguli  oris.  1,  Muscles  of  the 
os  hyoides.  m,  Sterno-cleido-mastoideus. 

Fig.  4.  Some  of  the  Muscles  of  the  Os  Hyoides  and  Sub- 
maxillary Gland. 

a,  Part  of  the  masseter  muscle,  b,  Posterior  head  of  the 
digastric,  c,  Its  anterior  head,  d d,  Sterno-hyoideus.  e,  Omo- 
hyoideus.  f,  Stylo-hyoideus.  g,  Submaxillary  gland  in  situ 


f;  c 


A 


i 


v';c 


Anatomy 


Explanation  of  the  Plates  of  the  Muscles.  441 

Fig.  5.  The  Submaxillary  Gland  and  Duct. 

a,  Musculus  mylo-hyoideus.  b,  Hyo-glossus.  c,  Submax- 
Illary  gland  removed  from  its  place,  d,  Its  duct. 

Plate  VII. 

Fig.  1.  The  Muscles  immediately  under  the  common  te- 
guments on  the  posterior  part  of  the  body,  are  represented  on 
the  right  side ; and  on  the  left  side  the  Muscles  are  seen 
which  come  in  view  when  the  exterior  ones  are  taken  away. 

Head. — AA,  Occipito-frontalis.  B,  Attollens  aurem.  C, 
Part  of  the  orbicularis  palpebrarum.  D,  Masseter.  E,  Ptery- 
goideus  interims. 

Trunk. — Right  side.  FFF,  Trapezius  seu  cucullaris. 
GGGG,  Latissimus  dorsi.  H,  Part  of  the  obliquus  externus 
abdominis. 

Trunk. — Leftside.  I,  Splenius.  K,  Part  of  the  cotnplexus. 
L,  Levator  scapulas.  M,  Rbomboides.  NN,  Serratus  posticus 
inferior.  O,  Part  of  the  longissimus  dorsi.  P,  Part  of  the 
sacro-lumbalis.  Q,  Part  of  the  semi-spinalis  dorsi.  R,  Part  of 
the  serratus  anticus  major.  S,  Part  of  the  obliquus  internus 
abdominis. 

Superior  Extremity. — Right  side.  T,  Deltoides.  U, 
Triceps  extensor  cubiti.  V,  Supinator  longus.  WW,  Ex- 
tensores  carpi  radialis  longior  and  brevior.  XX,  Extensor 
carpi  ulnaris.  YY,  Extensor  digitorum  communis.  Z,  Ab- 
ductor indicis.  12  3,  Extensores  pollicis. 

Superior  Extremity. — Left  side,  a,  Supra  Spinatus.  b, 
Infraspinatus,  c,  Teres  minor,  d,  Teres  major,  e,  Tri- 
ceps extensor  cubiti.  ff,  Extensores  carpi  radialis.  g,  Supi- 
nator brevis,  h,  Indicater.  12  3,  Extensores  pollicis.  i,  Ab- 
ductor minimi  digiti.  k,  Interossei. 

Inferior  Extremity. — Right  side.  1,  Glutseus  maximus. 
m,  Part  of  the  Glutseus  medius.  n,  Tensor  vaginae  femoris.  o. 
Gracilis,  pp,  Adductor  femoris  magnus.  q,  Part  of  the  vastus 
internus.  r,  Semimembranosus,  s,  Semitendinosus.  t,  Long 
head  of  the  biceps  flexor  cruris,  uu,  Gastrocnemius  externus 
seu  gemellus,  v,  Tendo  Achillis.  w,  Soleus  seu  gastrocne- 
miusfeternus.  xx,  Peronasus  longus  and  brevis,  y,  Tendons 
of  the  flexor  longus  digitorum  pedis; — and  under  them  *flexor 
brevis  digitorum  pedis,  z,  Abductor  minimi  digiti  pedis. 

Inferior  Extremity. — Left  side,  m,  n,  o,  pp,  q,  r,  s,  t , v, 
ww , xx,  y,  z,  Point  the  same  parts  as  in  the  right  side,  a,  Pyri- 
formis.  bb,  Gemini,  cc,  Obturator  internus.  d,  Quadratus  fe- 
moris. e,  Coceygaeus.  /,  The  short  head  of  the  biceps  flexor  cru- 
ris. gg,  Plantaris.  /i3Popliteus.  i,  Flexor  longus  pollicis  pedis , 

Vol.  n.  56 


442  Explanation  of  the  Plates  of  the  Muscles „ 

Fig.  2.  The  Palm  of  the  Left  Hand  after  the  common  Tegu- 
ments  are  removed,  to  show  the  Muscles  of  the  Fingers, 
a,  Tendon  of  the  flexor  carpi  radialis.  b,  Tendon  of  the  flex- 
or carpi  ulnaris.  c,  Tendons  of  the  flexor  sublimis  perforatus, 
profundus  perforans  and  lumbricales.  d,  Abductor  pollicis. 
ee,  Flexor  pollicis  longus.  f.  Flexor  pollicis  brevis,  g,  Palma- 
ris  brevis,  h,  Abductor  minimi  digiti.  i,  Ligamentum  carpi- 
annulare.  k,  A probe  put  under  the  tendons  of  the  flexor  di~ 
gitorum  sublimis;  which  are  performed  by  1,  the  flexor  digito- 
rum  profundus,  mmmm,  Lumbricales.  n,  Abductor  pollicis. 
Fig.  3.  A fore-view  of  the  foot  and  Tendons  of  the  flexores 
Digitorum. 

a,  Cut  extremity  of  the  tendo  Achillis.  b,  Upper  part  of  the 
astragalus,  c,  Os  calcis.  d,  Tendon  of  the  tibialis  anticus.  e, 
Tendon  of  the  extensor  pollicis  longus.  f,  Tendon  of  the 
peroneus  brevis,  g,  Tendons  of  the  flexor  digitorum  longus, 
with  the  non  us  Vesalii.  hh,  The  whole  of  the  flexor  digitorum 
brevis. 

Fig.  4.  Muscles  of  the  Anus, 
aa,  An  outline  of  the  buttocks,  and  upper  part  of  the  thighs, 
b,  The  testes  contained  in  the  scrotum,  cc,  Sphincter  ani. 
d,  Anus,  e,  Levator  ani.  ff,  Erector  penis,  gg,  Accelera- 
tor urinae.  h,  Corpus  cavernosum  urethrae. 

Fig.  3.  Muscles  of  the  Penis. 

aa,  b,  d,  ee,  ff,  h,  point  the  same  as  in  fig.  4.  c,  Sphincter 
ani.  gg,  Transversalis  penis. 

EXPLANATION  of  PLATES  VIII.  IX.  and  X. 

Plate  VIIL 

Fig.  1.  Shows  the  Contents  of  the  Thorax  and  Abdomen  In 

situ. 

l,  Top  of  the  trachea,  or  windpipe.  2 2,  The  internal  ju- 
gular veins.  3 3,  The  subclavian  veins.  4,  The  vena  cava  de- 
scendens.  5,  The  right  auricle  of  the  heart.  6,  The  right  ven- 
tricle. 7,  Part  of  the  left  ventricle.  8,  The  aorta  descendens. 
9,  The  pulmonary  artery.  10,  The  right  lung,  part  of  which, 
is  cut  off  to  show  the  great  blood  vessels.  11,  The  left  lung 
entire.  12  12,  The  anterior  edge  of  the  diaphragm.  1313, 
The  two  great  lobes  of  the  liver.  14,  The  ligamentum  rotun- 
dum.  15,  The  gall  bladder.  16,  The  stomach.  1717,  The 
jejunum  and  ilium.  18,  The  spleen. 


ANj\  T oMY 


Explanation  of  the  Plates  of  the  Muscles.  443 

Fig.  2.  Shows  the  organs  subservient  to  the  Chylopoietic  Vis- 
cera,— with  those  of  Urine  and  Generation. 

11,  The  under  side  of  the  two  great  lobes  of  the  liver,  a, 
Lobulus  spigelii.  2,  The  ligamentum  rotundum.  3,  The  gall- 
bladder. 4,  The  pancreas.  5,  The  spleen.  6 6,  The  Kid- 
neys. 7,  The  aorta  descendens.  8,  Vena  cava  ascendens. 
9 9,  The  renal  veins  covering  the  arteries.  10,  A probe  un- 
der the  spermatic  vessels  and  a bit  of  the  inferior  mesentric 
artery,  and  over  the  ureters.  1 1 11,  The  ureters.  12  12,  The 
iliac  arteries  and  veins.  13,  The  intestinum  rectum.  14, 
The  bladder  of  urine. 

Fig.  3.  Shows  the  Chylopoietic  Viscera,  and  Organs  subser- 
vient to  them,  taken  out  of  the  body  entire. 

AA,  The  under  side  of  the  two  great  lobes  of  the  liver.  B, 
Ligamentum  rotundum.  C,  The  gall-bladder.  D,  Ductus 
cysticus.  E,  Ductus  hepaticus.  F,  Ductus  communis  chole- 
dochus.  G,  Vena  portarum.  H,  Arteria  hepatica.  I,  The 
stomach.  KK,  Vense  and  arterise  gastro-epiploicae,  dextrae 
and  sinistrae.  LL,  Venae  and  arteriae  coronariae  ventriculi. 
M,  The  spleen.  NN,  Mesocolon,  with  its  vessels.  000,  In- 
testinum colon.  P,  One  of  the  ligaments  of  the  colon,  which 
is  a bundle  of  longitudinal  muscular  fibres.  QQQQ,  Jejunum 
and  ilium.  RR,  Sigmoid  flexure  of  the  colon  with  the  liga- 
ment continued,  and  over.  S,  The  intestinum  rectum.  TT, 
Levatores  ani.  U,  Sphincter  ani.  V,  The  place  to  which 
the  prostate  gland  is  connected.  W,  The  anus. 

Fig.  4.  Shows  the  Heart  of  a Foetus  at  the  full  time,  with 
the  Right  Auricle  cut  open  to  show  the  Foramen  Ovale,  or 
passage  between  both  Auricles. 

a,  The  right  ventricle,  b,  The  left  ventricle,  cc,  The  out- 
er side  of  the  right  auricle  stretched  out.  dd,  The  posterior 
side,  which  forms  the  anterior  side  of  the  septum,  e,  The 
foramen  ovale,  with  the  membrane  or  valve  which  covers  the 
left  side,  f,  Vena  cava  inferior  passing  through,  g,  A por- 
tion of  the  diaphragm. 

Fig.  5.  Shows  the  Heart  and  Large  Vessels  of  a Foetus  at 
the  full  time. 

a,  The  left  ventricle,  b,  The  right  ventricle,  c,  A part  of 
the  right  auricle,  d,  Left  auricle,  ee,  The  right  branch  of  the 
pulmonary  Artery,  f,  Arteria  pulmonalis.  gg,  The  left  branch 
of  the  pulmonary  artery,  with  a number  of  its  largest  branches 
dissected  from  the  lungs,  h,  The  canalis  arteriosus,  i,  The 
arch  of  the  aorta,  kk,  The  aorta  descendens.  1,  The  left  sub- 


444  Explanation  of  the  Plates  of  the  Muscles. 

clavian  artery,  m,  The  left  carotid  artery,  n,  The  right  caro- 
tid artery.  o,  The  right  subclavian  artery,  p,  The  origin  of  the 
right  carotid  and  right  subclavian  arteries  in  one  common 
trunk,  q,  The  vena  cava  superioror  descendens.  r,  The  right 
common  subclavian  vein,  s,  The  left  common  subclavian  vein. 

N.  B.  All  the  parts  described  in  this  figure  are  to  be  found 
in  the  adult,  except  the  canalis  arteriosus. 

Plate  IX. 

Fig.  1.  Exhibits  the  more  superficial  Lymphatic  Vessels  of 
the  Lower  Extremity. 

A,  The  spine  of  the  os  ilium.  B,  The  os  pubis,  c,  The 
iliac  artery.  D,  The  knee.  E,  E,  F,  Branches  of  the  crural  ar- 
tery. G,  The  musculus  gastrocnemius.  H,  The  tibia.  I,  The 
tendon  of  the  musculus  tibialis  anticus.  On  the  outlines,  a, 
A lymphatic  vessel  belonging  to  the  top  of  the  foot,  b,  Its 
first  division  into  branches,  c,  c,  c,  Other  divisions  of  the 
same  lymphatic  vessel,  d,  A small  lymphatic  gland,  e,  The 
lymphatic  vessels  which  lie  between  the  skin  and  the  muscles 
of  the  thigh,  ffj  Two  lymphatic  glands  at  the  upper  part  of 
the  thigh  below  the  groin,  gg,  Other  glands,  h,  A lympha- 
tic vessel  which  passes  by  the  side  of  those  glands  without 
communicating  with  them;  and  bending  towards  the  inside  of 
the  groin  at  (i,)  opens  into  the  lymphatic  gland  (k.)  11, 

Lymphatic  glands  in  the  groin,  which  are  common  to  the  lym- 
phatic vessels  of  the  genitals  and  those  of  the  lower  extremi- 
ty. m,  n,  A plexus  of  lymphatic  vessels  passing  on  the  in- 
side of  the  iliac  artery. 

Fig.  2.  Exhibits  a Back-view  of  the  Lower  Extremity  dis- 
sected so  as  to  show  the  deeper-seated  Lymphatic  Vessels 
which  accompany  the  Arteries. 

A,  The  os  pubis.  B,  The  tuberosity  of  the  ischium.  C,  That 
part  of  the  os  ilium  which  was  articulated  with  the  os  sacrum. 

D,  The  extremity  of  the  iliac  artery  appearing  above  the  groin. 

E,  The  knee.  FF,  The  two  cut  surfaces  of  the  triceps  muscle, 
which  was  divided  to  show  the  lymphatic  vessels  that  pass 
through  its  perforation  along  with  the  crural  artery.  G,  The 
edge  of  the  musculus  gracilis.  H,  The  gastrocnemius  and  so- 
leus  much  shrunk  by  being  dried,  and  by  the  soleus  being  se- 
parated from  the  tibia  to  expose  the  vessels.  I,  The  heel.  K, 
The  sole  of  the  foot.  L,  The  superficial  lymphatic  vessels 
passing  over  the  knee,  to  get  to  the  thigh.  On  the  outlines  ; 
M,  The  posterior  tibial  artery,  a,  A lymphatic  vessel  accom- 
panying the  posterior  tibial  artery,  b,  The  same  vessel  cross- 
ing the  artery,  c,  A small  1 vmphatic  gland,  through  which  this 

4 


Explanation  of  the  Plates  of  the  Muscles.  445 

deep-seated  lymphatic  vessel  passes,  d,  The  lymphatic  vessel 
passing  under  a small  part  of  the  soleus,  which  is  left  attached 
to  the  bone,  the  rest  being  removed.  e,  The  lymphatic  vessel 
crossing  the  popliteal  artery,  f,  g,  h,  Lymphatic  glands  in  the 
ham,,  through  which  the  lymphatic  vessel  passes,  i,  The  lym- 
phatic vessel  passing  with  the  crural  artery,  through  the  perfo- 
ration of  the  triceps  muscle,  k,  The  lymphatic  vessel,  after  it 
has  passed  the  perforation  of  the  triceps,  dividing  into  branches 
which  embrace  the  artery  (1.)  m,  A lymphatic  gland  belonging 
to  the  deep-seated  lymphatic  vessel.  At  this  place  those  vessels 
pass  to  the  fore  part  of  the  groin  where  they  communicate  with 
the  superficial  lymphatic  vessel,  n,  A part  of  the  superficial 
lymphatic  vessel  appearing  on  the  brim  of  the  pelvis. 

Fig.  3.  Exhibits  the  Trunk  of  the  Human  Subject  prepared 
to  show  the  Lymphatic  Vessels  and  the  Ductus  Thoracicus. 

A,  The  neck.  BB,  The  two  jugular  veins.  C,  The  vena 
cava  superior.  DDDD,  The  subclavian  veins.  E,  The  begin- 
ning of  the  aorta,  pulled  to  the  left  side  by  means  of  a ligature, 
in  order  to  show  the  thoracic  duct  behind  it.  F,  The  branches 
arising  from  the  curvature  of  the  aorta.  GG,  The  two  carotid 
arteries.  HH,  The  first  ribs.  II,  The  trachea.  KK,  The  spine. 
LL,  The  vena  azygos.  MM,  The  descending  aorta.  N,  The 
cceliac  artery,  dividing  into  three  branches.  0,  The  superior 
mesenteric  artery.  P,  The  right  crus  diaphragm atis.  QQ,  The 
two  kidneys.  R,  The  right  emulgent  artery.  SS,  The  external 
iliac  arteries,  g,  d,  The  psoas  muscles.  T,  The  internal  iliac 
artery.  U,  The  cavity  of  the  pelvis.  XX,  The  spine  of  the  os 
ilium.  YY,  The  groins,  a,  A lymphatic  gland  in  the  groin, 
into  which  lymphatic  vessels  from  the  lower  extremity  are  seen 
to  enter,  bb,  The  lymphatic  vessels  of  the  lower  extremities 
passing  under  Poupart’s  ligament,  cc,  A plexus  of  the  lympha- 
tic vessels  lying  on  each  side  of  the  pelvis,  d,  The  psoas  muscle 
with  lymphatic  vessels  lying  upon  its  inside,  e,  A plexus  of 
lymphatics,  which  having  passed  over  the  brim  of  the  pelvis  at 
(c,)  naving  entered  the  cavity  of  the  pelvis,  and  received  the 
lymphatic  vessels  belonging  to  the  viscera  contained  in  that  ca- 
vity, next  ascends  and  passes  behind  the  illiac  artery  to  (g.)  f 
Some  lymphatic  vessels  of  the  left  side  passing  over  the  upper 
part  of  the  os  sacrum:  to  meet  those  of  the  right  side,  g,  The 
right  psoas,  with  a large  plexus  of  lymphatics  lying  on  its  inside. 
M,  The  plexus  lying  on  each  side  of  the  spine.  Hi,  Spaces 
occupied  by  the  lymphatic  glands,  k,  The  trunk  of  the  lacteals 
lying  on  the  under  side  of  the  superior  mesenteric  artery.  /,  The 
same  dividiug  into  two  branches,  one  of  which  passes  on  each 


446  Explanation  of  the  Plates  of  the  Muscles. 

side  of  the  aorta;  that  of  the  right  side  being  seen  to  enter  the 
thoracic  duct  at  ( m .)  m,  The  thoracic  duct  beginning  from 
the  large  lymphatics,  n,  The  duct  passing  under  the  lower 
part  of  the  crus  diaphragmatis,  and  under  the  right  emulgent 
artery,  o,  The  thoracic  duct  penetrating  the  thorax,  p,  Some 
lymphatic  vessels  joining  that  duct  in  the  thorax,  q,  The  tho- 
racic duct  passing  under  the  curvature  of  the  aorta  to  get  to 
the  left  subclavian  vein.  The  aorta  being  drawn  aside  to  show 
the  duct,  r,  A plexus  of  lymphatic  vessels  passing  upon  the 
trachea  from  the  thyroid  gland  to  the  thoracic  duct. 

Plate  X. 

Fig.  1.  Represents  the  Under  and  Posterior  Side  of  the 
Bladder  of  Urine,  &c. 

a,  The  bladder,  bb,  The  insertion  of  the  ureters,  cc,  The 
vasa  deferentia,  which  convey  the  semen  from  the  testicles  to 
dd.  The  vesiculae  seminales, — and  pass  through  e.  The  pros- 
tate gland,  to  discharge  themselves  into  f.  The  beginning  of 
the  urethra. 

Fig.  2.  A transverse  Section  of  the  Penis. 

gg,  Corpora  cavernosa  penis,  h,  Corpus  cavernosum  ure- 
thrae. i.  Urethra,  k,  Septum  penis.  11,  The  septum  be- 
tween the  corpus  cavernosum  urethrae  and  that  of  the  penis. 

Fig.  3.  A Longitudinal  Section  of  the  Penis. 

mm,  The  corpora  cavernosa  penis,  divided  by  o,  The  sep- 
tum penis,  n,  The  corpus  cavernosum  glandis,  which  is  the 
continuation  of  that  of  the  urethra. 

Fig.  4.  Represents  the  Female  Organs  of  Generation. 

a,  That  side  of  the  uterus  which  is  next  to  the  os  sacrum. 
1,  Its  fundus.  2,  Its  cervix,  bb,  The  fallopian  or  uterine 
tubes,  which  open  into  the  cavity  of  the  uterus; — but  the  other 
end  is  open  within  the  pelvis,  and  surrounded  by  c c,  The  fim- 
briae. d d,  The  ovaria.  e,  The  os  internum  uteri,  or  mouth 
of  the  womb,  ff,  The  ligamentum  rotundum,  which  passes 
without  the  belly,  and  is  fixed  to  the  labia  pudendi.  gg,  The 
cut  edges  of  the  ligamenta  lata,  which  connect  the  uterus  to 
the  pelvis,  h.  The  inside  of  the  vagina,  i,  The  orifice  of  the 
urethra,  k,  The  clitoris  surrounded  by  (1,)  The  praeptium. 
mm,  The  labia  pudendi.  nn,  The  nympbae. 

Fig.  5.  Shows  the  Spermatic  Ducts  of  the  Testicle  filled 
with  Mercury. 

A,  The  vas  deferens.  B,  Its  beginning,  which  forms  the 


/<  w . 


Akat  omt 


A N ATOMY 


Explanation  of  Vie  Plates  of  the  Muscles . 447 

posterior  part  of  the  epididymis.  C,  The  middle  of  the  epi- 
didymis,  composed  of  serpentine  ducts.  D,  The  head  or  an- 
terior part  of  the  epididymis  unravelled,  e e e e,  The  whole 
ducts  which  compose  the  head  of  the  epididymis  unravelled, 
f f,  The  vasa  deferentia.  g g,  Rete  testis,  h h,  Some  recti- 
linear ducts  which  send  off  the  vasa  deferentia.  i i,  The  sub- 
stance of  the  testicle. 

Fig.  6.  The  right  Testicle  entire,  and  the  Epididymis  filled 
with  Mercury. 

A,  The  beginning  of  the  vas  deferens.  B,  The  vas  deferens 
ascending  towards  the  abdomen.  C,  The  posterior  part  of  the 
epididymis,  named  globus  minor.  D,  The  spermatic  vessels 
enclosed  in  cellular  substance.  E,  The  body  of  the  epididy- 
mis. F,  Its  head,  named  globus  major.  G,  Its  beginning  from 
the  testicle.  H,  The  body  of  the  testicle,  enclosed  in  the  tu- 
nica albuginea. 


EXPLANATION  of  PLATE  XI. 

This  plate  represents  the  Heart  in  situ,  all  the  large  Arte- 
ries and  Veins,  with  some  of  the  Muscles,  &c. 

Muscles,  &c. — Superior  Extremity. — a,  Masseter.  b, 
Complexus.  C,  Digastricus.  d,  Os  hyoides.  e,  Thyroid  gland, 
f,  Levator  scapulae,  g,  Cucullaris.  h h,  The  clavicles,  cut.  i. 
The  deltoid  muscle,  k,  Biceps  flexor  cubiti.  cut.  1,  Coraco- 
brachialis.  m,  Triceps  extensor  cubiti.  n,  The  heads  of  the 
pronator  teres,  flexor  carpi  radiales,  and  flexor  digitorum  sub- 
limis,  cut.  o,  The  flexor  carpi-ulnaris,  cut  at  its  extremity. 

p,  Flexor  digitorum  profundus,  q,  Supinator  radii  longus, 
cut  at  its  extremity,  r,  Ligamentum  carpi  transversale.  s, 
Extensores  carpi  radiales.  t,  Latissimus  dorsi.  u,  Anterior 
edge  of  the  serratus  anticus  major,  vv,  The  inferior  part  of 
the  diaphragm,  ww,  Its  anterior  edge  cut.  xx,  The  kidneys, 
y,  Transversus  abdominus.  z,  Os  ilium. 

Inferior  Extremity. — a,  Psoas  magnus.  b,  Iliacus  inter- 
nus.  c,  The  fleshy  origin  of  the  tensor  vagina  femoris.  dd} 
The  ossa  pubis  cut  from  each  other,  e,  Musculus  pectineus 
cut  from  its  origin,  f,  Short  head  of  the  triceps  abductor  fe- 
moris cut.  g,  The  great  head  of  the  triceps,  h,  The  long 
head  cut.  i,  Vastus  internus.  k,  Vastus  externus.  I,  Cru- 
reus.  m,  Gemellus,  n,  Soleus.  o,  Tibia,  p,  Peroneus  longus. 

q,  Peroneus  brevis,  r,  Fibula. 

Heart  and  Blood-vessels. — A,  The  heart,  with  the  co- 
ronary artery  and  veins.  B,  The  right  auricle  of  the  heart.  C, 
The  aorta  ascendens.  D,  The  left  subclavian  artery.  E,  The 


448  Explanation  of  the  Plates  of  the  Muscles. 

left  carotid  artery.  F,  The  common  trunk  which  sends  oft' the 
right  subclavian  and  right  carotid  arteries.  G,  The  carotis  ex- 
terna. H,  Arteria  facialis,  which  sends  off  the  coronary  arte- 
ries of  the  lips.  I,  Arteria  temporalis  profunda.  K,  Aorta  de- 
scendens.  LL,  The  illiac  arteries,  which  sends  oft'  MM,  The 
femoral  or  crural  arteries.  N.  B.  The  other  arteries  in  this 
figure  have  the  same  distribution  as  the  veins  of  the  same 
name : — And  generally,  in  the  anatomical  plates,  the  descrip- 
tion to  be  found  on  the  one  side,  points  out  the  same  parts  in 
the  other.  1,  The  frontal  vein.  2,  The  facial  vein.  3,  Vena 
temporalis  profunda.  4,  Vena  occipitalis.  5,  Vena  jugulads 
externa.  6,  Vena  jugularis  interna,  covering  the  arteria  caro- 
tis communis.  7,  The  vascular  arch  on  the  palm  of  the  hand, 
which  is  formed  by,  8,  The  radial  artery  and  vein,  and,  9, 
The  ulnar  artery  and  vein.  10  10,  Cephalic  vein.  1 1,  Basilic 
vein,  that  on  the  right  side  cut.  12,  Median  vein.  13,  The 
humeral  vein,  which,  with  the  median,  covers  the  humeral  ar- 
tery. 14  14,  The  external  thoracic  or  mammary  arteries  and 
veins.  15,  The  axillary  vein,  covering  the  artery.  16  16,  The 
subclavian  veins,  which,  with  (6  6)  the  jugulars,  form,  17,  The 
vena  cava  superior.  18,  The  cutaneous  arch  of  veins  on  the 
fore  part  of  the  foot.  19,  The  vena  tibialis  antica,  covering  the 
artery.  20,  The  vena  profunda  femoris,  covering  the  artery. 
21,  The  upper  part  of  the  vena  saphena  major.  22,  The  fe- 
moral vein.  2323,  The  illiac  veins.  24  24,  Vena  cava  infe- 
rior. 25  25,  The  renal  veins  covering  the  arteries.  26  26, 
The  diaphragmatic  veins. 


EXPLANATION  of  PLATE  XII. 

Fig.  1.  Represents  the  Inferior  part  of  the  Brain; — the  An- 
terior part  of  the  whole  Spine,  including  the  Medulla  Spina- 
lis;— with  the  origin  and  large  portions  of  all  the  Nerves. 

AA,  The  anterior  lobes  of  the  cerebrum.  BB,  The  lateral 
lobes  of  the  cerebrum.  CC,  The  two  lobes  of  the  cerebellum. 
D,  Tuber  annulare.  E,  The  passage  from  the  third  ventricle 
to  the  infundibulum.  F,  The  medulla  oblongata,  which  sends 
off  the  medulla  spinalis  through  the  spine.  GG,  That  part  of 
the  os  occipitis  which  is  placed  above  (HH)  the  transverse 
processes  of  the  first  cervical  vertebra.  II,  &c.  The  seven 
cervical  vertebrae,  with  their  intermediate  cartilages.  KK, 
&c.  The  twelve  dorsal  vertebrae,  with  their  intermediate  car- 
tilages. LL,  &c.  The  five  lumbar  vertebrae,  with  their  inter- 
mediate cartilages.  M,  The  os  sacrum.  N,  The  os  coccygis. 


Ill* 


Explanation  of  the  Plates  of  the  Muscles . 449 

Nerves. — 1 1,  The  first  pair  of  nerves,  named  olfactory 9 
which  go  to  the  nose.  2 2,  The  second  pair  named  optic , which 
goes  to  form  the  tunica  retina  of  the  eye.  3 3,  The  third  pair, 
named  motor  oculi ; it  supplies  most  of  the  muscles  of  the 
eye-ball.  4 4,  The  fourth  pair,  named  pathetic , — which  is 
wholly  spent  upon  the  musculus  trochlearis  of  the  eye.  5 5, 
The  fifth  pair  divides  into  three  branches. — The  first,  named 
ophthalmic,  goes  to  the  orbit,  supplies  the  lachrymal  gland,  and 
sends  branches  out  to  the  forehead  and  nose. — The  second, 
named  superior  maxillary,  supplies  the  teeth  of  the  upper 
jaw,  and  some  of  the  muscles  of  the  lips. — The  third,  named 
inferior  maxillary,  is  spent  upon  the  muscles  and  teeth  of  the 
lower  jaw,  tongue,  and  muscles  of  the  lips.  6 6,  The  sixth 
pair,  which  after  sending  oft'  the  beginning  of  the  intercostal 
or  great  sympathetic,  is  spent  upon  the  abductor  oculi.  7 7, 
The  seventh  pair,  named  auditory,  divides  into  two  branches.-- 
The  largest,  named  portio  mollis , is  spent  upon  the  internal 
ear.  The  smallest,  portio  dura , joins  to  the  fifth  pair  within 
the  internal  ear  by  a reflected  branch  from  the  second  of  the 
fifth ; and  within  the  tympanum,  by  a branch  from  the  third 
of  the  fifth,  named  chorda  tympuni. — >Vid.  fig.  3.  near  B 8 8, 
&c.  The  eighth  pair,  named  par  vugum, — which  accompanies 
the  intercostal,  and  is  spent  upon  the  tongue,  larynx,  pharynx, 
lungs,  and  abdominal  viscera.  9 9,  The  ninth  pair,  which  are 
spent  upon  the  tongue.  10  10,  &c.  The  intercostal,  or  great 
sympathetic,  which  is  seen  from  the  sixth  pair  to  the  bottom 
of  the  pelvis  on  each  side  of  the  spine,  and  joining  with  all 
the  nerves  of  the  spine; — In  its  progress  supplying  the  heart, 
and,  with  the  par  vagum,  the  contents  of  the  abdomen  and 
pelvis.  1111,  The  accessorius,  which  is  spent  upon  the  ster- 
no-cleido-mastoideus  and  trapezius  muscles.  12  12,  The  first 
cervical  nerves; — 13  13,  The  second  cervical  nerves; — both 
spent  upon  the  muscles  that  lie  on  the  neck,  and  teguments 
of  the  neck  and  head.  1414,  The  third  cervical  nerves,  which, 
after  sending  off,  (15  15,  &c.)  the  phrenic  nerves  to  the  dia- 
phragm, supply  the  muscles  and  teguments  that  lie  on  the 
side  of  the  neck  and  top  of  the  shoulder.  16  16,  The  brachial 
plexus,  formed  by  the  fourth,  fifth,  sixth,  seventh  cervicals, 
and  first  dorsal  nerves  : which  supply  the  muscles  and  tegu- 
ments of  the  superior  extremity.  17  17,  The  twelve  dorsal, 
or  proper  intercostal  nerves,  which  are  spent  upon  the  inter- 
costal muscles  and  some  of  the  large  muscles  which  lie  upon 
the  thorax.  IS  18,  The  five  lumbar  pairs  of  nerves,  which 
supply  the  lumbar  and  abdominal  muscles,  and  some  of  the 
teguments  and  muscles  of  the  inferior  extremity.  19  19.  The 
Vol.  ii,  57 


450  Explanation  of  the  Plates  of  the  Muscles, 

sacro-sciatic  or  posterior  crural  nerve,  formed  by  the  two  in- 
ferior lumbar,  and  three  superior  of  the  os  sacrum.  This  large 
nerve  supplies  the  greatest  part  of  the  muscles  and  teguments 
of  the  iuferior  extremity.  20,  The  stomachic  plexus,  formed 
by  the  eighth  pair.  21  21,  Branches  of  the  solar  or  cceliae 
plexus,  formed  by  the  eighth  pair  and  intercostals,  which  sup- 
ply the  stomach  and  chylopoietic  viscera.  22  22,  Branches  of 
the  superior  and  inferior  mesenteric  plexuses,  formed  by  the 
eighth  pair  and  intercostals,  which  supply  the  chylopoietic  vis- 
cera, with  part  of  the  organs  of  urine  and  generation.  23  23, 
Nerves  which  accompany  the  spermatic  cord.  24  24,  The  hy- 
pogastric plexus,  which  supplies  the  organs  of  urine  and  gene- 
ration within  the  pelvis. 

Fig.  2, 3, 4,  5,  Show  different  Views  of  the  Inferior  part  of  the 
Brain,  cut  perpendicularly  through  the  Middle, — with  the 
Origin  and  large  Portions  of  all  the  Nerves  which  pass  but 
through  the  Bones  of  the  Cranium,— and  the  three  first 
Cervicals. 

A,  The  anterior  lobe.  B,  The  lateral  lobe  of  the  cerebrum, 
C,  Onehrf  the  lobes  of  the  cerebellum.  D,  Tuber  annulare. 

E,  Corpus  pyramidale,  in  the  middle  of  the  medulla  oblongata, 

F,  The  corpus  olivare,  in  the  side  of  the  medulla  oblongata, 

G,  The  medulla  oblongata.  H,  The  medulla  spinalis. 
Nerves.— 1 23  45  6 7 8 and  9,  Pairs  of  Nerves.  10  10, 

Nerves  accessorius,  which  comes  from — 11,  12,  and  13,  The 
three  first  cervical  nerves. 


EXPLANATION  of  PLATE  XIII. 

Fig.  1.  Shows  the  Lachrymal  Canals,  after  the  Common  Te- 
guments and  Bones  have  been  cut  away, 
a,  The  lachrymal  gland,  b,  The  tivo  puncta  lachrymalia, 
from  which  the  two  lachrymal  canals  proceed  to  c,  The  lach- 
rymal sac.  d,  The  large  lachrymal  duct,  e,  Its  opening  into 
the  nose,  f,  The  carunca  lachrymal  is.  g,  The  eye-ball. 

Fig.  2,  An  interior  View  of  the  Coats  and  Humours  of  the 

Eye. 

a a a a,  The  tunica  sclerotica  cut  in  four  angles,  and  turned 
back,  bbbb,  The  tunica  clioroides  adhering  to  the  inside  of 
the  sclerotica  and  the  ciliary  vessels  are  seen  passing  over — 
cc.  The  retina  which  covers  the  vitreous  humour,  dd,  The 
ciliary  processes,  which  were  continued  from  the  choroid  coat, 
a e,  The  iris  f,  The  pupil. 


Anatomy  plate  xm . 


Explanation  of  the  Plates  of  the  Muscles.  451 

Fig.  3.  Shows  the  Optic  Nerves,  and  Muscles  of  the  Eye. 
a,  a.  The  two  optic  nerves  before  they  meet,  b,  The  two 
optic  nerves  conjoined,  c,  The  right  optic  nerve,  d,  Muscu- 
lus.attollens  palpebrse  superioris.  e,  Attollens  oculi.  f,  Ab- 
ductor. gg,  Obliquus  superior,  or  trochlearis.  h,  Abductor, 
i,  The  eye-ball. 

Fig.  4.  Shows  the  Eye-ball  with  its  Muscles, 
a,  The  optic  nerve,  b,  Musculus  trochlearis.  c,  Part  of 
the  os  frontis,  to  which  the  trochlea  or  pulley  is  fixed  through 
which, — d,  The  tendons  of  the  trochlearis  pass,  e,  Attollens 
oculi.  f,  Adductor  oculi.  g,  Abductor  oculi.  h,  Obliquus  in- 
ferior. i,  Part  of  the  superior  maxillary  bone  to  which  it  is 
fixed,  k,  The  eye-ball. 

Fig.  5.  Represents  the  Nerves  and  Muscles  of  the  Right 
Eye,  after  part  of  the  Bones  of  the  orbit  have  been  cut 
away. 

A,  The  eye-ball.  B,  The  lachrymal  gland.  C,  Musculus 
abductor  oculi.  D,  Attollens.  E,  Levator  palpebras  superi- 
oris. F,  Depressor  oculi.  G,  Abductor.  H,  Obliquus  superior, 
with  its  pulley.  I,  Its  insertion  into  the  sclerotic  coat.  K, 
Part  of  the  obliquus  inferior.  L,  The  anterior  part  of  the  os 
frontis,  cut.  M,  The  crista  galli  of  the  ethmoid  bone.  N, 
The  posterior  part  of  the  sphenoid  bone.  0,  Transverse  spi- 
nous process  of  the  sphenoid  bone.  P,  The  carotid  artery, 
denuded  where  it  passes  through  the  bones.  Q,  The  carotid 
artery  within  the  cranium.  R,  The  ocular  artery. 

Nerves.— a a,  The  optic  nerve,—- b,  The  third  pair,  c,  Its 
joining  with  a branch  of  the  first  branch  of  the  fifth  pair,  to 
form  1, — The  lenticular  ganglion,  which  sends  off  the  ciliary 
nerves,  d.  ee,  The  fourth  pair,  f,  The  trunk  of  the  fifth  pair, 
g,  The  first  branch  of  the  fifth  pair,  named  ophthalmic,  h, 
The  frontal  branch  of  it.  i,  Its  ciliary  branches,  along  with 
which  the  nasal  twig  is  sent  to  the  nose,  k,  Its  branch  to  the 
lachrymal  gland.  1,  The  lenticular  ganglion,  m,  The  second 
branch  of  the  fifth  pair,  named  superior  maxillary,  n,  The 
third  branch  of  the  fifth  pair,  named  inferior  maxillary,  o, 
The  sixth  pair  of  nerves — which  sends  oft'  p,  The  beginning 
of  the  great  sympathetic,  q,  The  remainder  of  the  sixth  pair, 
spent  on  c,  The  abductor  oculi. 

Fig.  6.  Represents  the  head  of  a youth,  where  the  upper  part 
of  the  cranium  is  sawed  off, —to  show  the  upper  part  of  the 
brain,  covered  by  the  pia  mater,  the  vessels  of  which  are 
minutely  filled  with  wax. 

AA,  The  cut  edges  of  the  upper  part  of  the  cranium.  B. 


452  Explanation  of  ike  Plates  of  the  Muscles. 

The  two  tables  and  intermediate  diploe.  BB,  The  two  hemi- 
spheres of  the  cerebrum.  CC,  The  incisure  made  by  the  falx, 
D,  Part  of  the  tentorium  cerebello  super  expansum.  E,  Part 
of  the  falx,  which  is  fixed  to  the  crista  galli. 

Fig.  7.  Represents  the  parts  of  the  External  Ear,  with  the 
Parotid  Gland  and  its  Duct. 

a a,  The  helix,  b,  The  antihelix,  c.  The  antitragus,  d,  The 
tragus,  e,  The  lobe  of  the  ear.  f,  The  cavitas  innominata.  g, 
The  scapha.  h,  The  concha,  i i,  The  parotid  gland,  k,  A 
lymphatic  gland,  which  is  often  found  before  the  tragus.  1, 
The  duct  of  the  parotid  gland,  m,  its  opening  into  the  mouth. 
Fig.  8.  A view  of  the  posterior  part  of  the  external  ear,  mea- 
tus auditorius,  tympanum  with  its  small  bones  and  Eusta- 
chian tube,  of  the  right  side. 

a,  The  back  part  of  the  meatus,  with  the  small  ceruminous 
glands,  b,  The  incus,  c,  Malleus,  d,  The  chorda  tympani.  e, 
Membrana  tympani.  f,  The  Eustachian  tube,  g,  Its  mouth 
from  the  fauces. 

Fig.  9.  Represents  the  anterior  part  of  the  right  external  ear, 
the  cavity  of  the  tympanum — it9  small  bones,  cochlea,  and 
semicircular  canals. 

a,  The  malleus,  b,  Incus,  with  its  long  leg,  resting  upon 
the  stapes,  c,  Membrana  tympani.  d,  e,  The  Eustachian  tube 
covered  by  part  of — f f,  The  Musculus  circumilexus  palati.  1, 
2,  3,  The  three  semicircular  canals.  4,  The  vestibule.  5,  The 
cochlea.  6,  The  portio  mollis  of  the  seventh  pair  of  nerves. 
Fig.  10.  Shows  the  muscles  which  compose  the  fleshy  sub- 
stance of  the  Tongue. 

a a,  The  tip  of  the  tongue,  with  some  of  the  papillse  mini- 
mse.  b,  The  root  of  the  tongue,  c,  Part  of  the  membrane  of 
the  tongue,  which  covered  the  epiglottis,  d d,  Part  of  the  mus- 
culus hyo-glossus.  e,  The  lingualis.  f,  Genio-glossus.  g g. 
Part  of  the  stylo-glossus. 


JgT 


I 

Wistar 

1827 

v.  2 


